Once you've got your CCNA, you're ready to move on to the next level, the Professional certifications. For years, Cisco had one Professional certification, the Cisco Certified Network Professional (CCNP) certification. Over time, Cisco has expanded this level of certifications to include the Cisco Certified Security Professional (CCSP) and Cisco Certified Voice Professional (CCVP).
With security and voice being the two most rapidly expanding areas of today's networks, some new CCNAs consider going after the CCSP or CCVP without first adding the CCNP to their resume.
While it's temping to hurry up and get a Cisco security or voice certification, the best thing you can do for your networking career is achieve your CCNP certification first, then decide on the CCVP or CCSP.
Why? Because the CCNA is just the tip of a very large iceberg when it comes to routing and switching. It's a very important accomplishment, and the CCNA is indeed the foundation of your networking career, but you need to add on to that level of understanding routing and switching before moving on to more specialized areas.
Two examples are OSPF and BGP. You learn about the theory of OSPF and some basic and intermediate configurations of that protocol in your CCNA studies, but the knowledge you acquire of OSPF in your CCNP studies is invaluable. As for BGP, there is no BGP in the CCNA curriculum, but it is a great idea to have some BGP knowledge in today's networks. It's also good for your career.
I know it is a huge temptation to go after the security and voice certifications while not paying attention to the CCNP. Do yourself a huge favor and add the tremendous amount of routing and switching knowledge needed for the CCNP to your knowledgebase, and you can then move on to the CCSP or CCVP. Even better, you'll be better prepared to climb the biggest certification mountain around - the CCIE!
Showing posts with label bsci. Show all posts
Showing posts with label bsci. Show all posts
Saturday, December 27, 2008
Tips On Buying A Cisco CCNA / CCNP Home Lab Kit
Buying a CCNA / CCNP home lab is the best way to be totally prepared for your Cisco exams. Most home labs are put together one router or switch at a time, but many CCNA / CCNP candidates prefer to buy kits where you get multiple routers and switches, along with all the cables and other connection devices you'll need.
While this is a good idea, keep a few things in mind when purchasing Cisco home lab kits.
Don't buy anything you don't need. The problem is that when you're first starting out with your Cisco home lab, you don't know everything that you need. (I sure didn't!) Keep in mind that you only need one transceiver per AUI port on a Cisco router, so if you're getting routers with two AUI ports in all, you don't need five transceivers in the kit. It doesn't hurt to have one spare, but three is a little too much.
More importantly, don't buy kits with old CCNA or CCNP study guides included. I've seen kits with books that were three years old and were of no use to the candidate. If you see a kit that looks good but includes books or manuals you just don't want, ask the vendor for a price that doesn't include the books. It never hurts to ask.
Watch the IOS version. Unless you've got access to IOS upgrades, you'll be working with the IOS version that's on the routers and switches when you buy the kit for a while. You don't necessarily need the latest and greatest IOS version for CCNA study, but don't buy routers with IOS versions beginning with "10" unless you have an IOS to upgrade them with. (And make sure the routers have enough memory to handle the IOS you plan on putting on them.)
Purchasing a Cisco CCNA / CCNP Home Lab is one of the best investments in your career that you will ever make. Exercise just a bit of caution when purchasing your kit, and you'll be on your way to true Cisco success, in the exam room and on your network!
While this is a good idea, keep a few things in mind when purchasing Cisco home lab kits.
Don't buy anything you don't need. The problem is that when you're first starting out with your Cisco home lab, you don't know everything that you need. (I sure didn't!) Keep in mind that you only need one transceiver per AUI port on a Cisco router, so if you're getting routers with two AUI ports in all, you don't need five transceivers in the kit. It doesn't hurt to have one spare, but three is a little too much.
More importantly, don't buy kits with old CCNA or CCNP study guides included. I've seen kits with books that were three years old and were of no use to the candidate. If you see a kit that looks good but includes books or manuals you just don't want, ask the vendor for a price that doesn't include the books. It never hurts to ask.
Watch the IOS version. Unless you've got access to IOS upgrades, you'll be working with the IOS version that's on the routers and switches when you buy the kit for a while. You don't necessarily need the latest and greatest IOS version for CCNA study, but don't buy routers with IOS versions beginning with "10" unless you have an IOS to upgrade them with. (And make sure the routers have enough memory to handle the IOS you plan on putting on them.)
Purchasing a Cisco CCNA / CCNP Home Lab is one of the best investments in your career that you will ever make. Exercise just a bit of caution when purchasing your kit, and you'll be on your way to true Cisco success, in the exam room and on your network!
Passing The CCNA and CCNP Exams: Setup Mode
CCNA and CCNP candidates need to know all about Setup Mode, why a router goes into that mode, and as you'll see, how to get out of that mode. Practicing Setup Mode at work is a good way to get fired, though, so you need to practice this on your CCNA / CCNP home lab or rack rental. In this article, we'll take a look at a Cisco 2500 router going into setup mode and a few tips that will help you pass the exams and excel at your job.
First, why does a router go into Setup Mode in the first place? When a Cisco router boots up, the router looks into Non-Volatile RAM (NVRAM) for the startup configuration file. If such a file is not found, and the router has not been programmed to look to a TFTP server for this file, the router enters setup mode.
The most common reason for a router not to have a startup configuration file is that the file's been erased. We will now erase this file on our 2500 router. As you'll see, the Cisco router warns us about erasing NVRAM and makes us confirm this choice, which it acknowledges with the OK message.
R1#write erase
Erasing the nvram filesystem will remove all files! Continue? [confirm]
[OK]
Erase of nvram: complete
R1#
The router will now be reloaded. There is a slightly misleading message displayed during reboot:
R1#reload
Proceed with reload? [confirm]
00:15:21: %SYS-5-RELOAD: Reload requested
System Bootstrap, Version 11.0(10c)XB1, PLATFORM SPECIFIC RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1997 by cisco Systems
2500 processor with 14336 Kbytes of main memory
Notice: NVRAM invalid, possibly due to write erase.
That notice doesn't mean the NVRAM is corrupt or unusable; this message means the NVRAM doesn't have a startup configuration file.
The router will continue to boot and finally present you with this prompt:
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]:
Almost every WAN engineer I know answers "no" to this question, because Setup Mode is a long, clumsy way to set up a router (in my humble opinion). We will answer "yes" in order to see this mode in action.
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]: y
At any point you may enter a question mark '?' for help.
Use ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets '[]'.
Basic management setup configures only enough connectivity
for management of the system, extended setup will ask you
to configure each interface on the system
Would you like to enter basic management setup? [yes/no]: y
Configuring global parameters:
Enter host name [Router]: R1
The enable secret is a password used to protect access to
privileged EXEC and configuration modes. This password, after
entered, becomes encrypted in the configuration.
Enter enable secret:
% No defaulting allowed
Enter enable secret:
Already, there's something about Setup Mode that you might not like. This mode forces you to set an enable password and an enable secret password. As you continue in this mode, you'll see this mode ask you questions about every single interface on the router, even if you're not planning to use that interface. Using Setup Mode really does get quite old after a while, again in my opinion.
One of the most important things about Setup Mode is knowing how to get out of it without saving the configuration. One way is at the very end of this mode, where you can answer "no" to "Do you want to save this configuration?" I personally never make it that far! Instead of waiting until the end of Setup Mode, we can use the CTRL-C key combination to abort this mode and ignore the changes.
Configuration aborted, no changes made.
Press RETURN to get started!
Setup Mode is not a mode that CCNA and CCNP candidates get a great deal of practice with, but you will be tested on your knowledge about it both in the exam room and on the job. And once you start configuring a router with this mode, you'll be glad you know how to get out of it!
First, why does a router go into Setup Mode in the first place? When a Cisco router boots up, the router looks into Non-Volatile RAM (NVRAM) for the startup configuration file. If such a file is not found, and the router has not been programmed to look to a TFTP server for this file, the router enters setup mode.
The most common reason for a router not to have a startup configuration file is that the file's been erased. We will now erase this file on our 2500 router. As you'll see, the Cisco router warns us about erasing NVRAM and makes us confirm this choice, which it acknowledges with the OK message.
R1#write erase
Erasing the nvram filesystem will remove all files! Continue? [confirm]
[OK]
Erase of nvram: complete
R1#
The router will now be reloaded. There is a slightly misleading message displayed during reboot:
R1#reload
Proceed with reload? [confirm]
00:15:21: %SYS-5-RELOAD: Reload requested
System Bootstrap, Version 11.0(10c)XB1, PLATFORM SPECIFIC RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1997 by cisco Systems
2500 processor with 14336 Kbytes of main memory
Notice: NVRAM invalid, possibly due to write erase.
That notice doesn't mean the NVRAM is corrupt or unusable; this message means the NVRAM doesn't have a startup configuration file.
The router will continue to boot and finally present you with this prompt:
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]:
Almost every WAN engineer I know answers "no" to this question, because Setup Mode is a long, clumsy way to set up a router (in my humble opinion). We will answer "yes" in order to see this mode in action.
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]: y
At any point you may enter a question mark '?' for help.
Use ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets '[]'.
Basic management setup configures only enough connectivity
for management of the system, extended setup will ask you
to configure each interface on the system
Would you like to enter basic management setup? [yes/no]: y
Configuring global parameters:
Enter host name [Router]: R1
The enable secret is a password used to protect access to
privileged EXEC and configuration modes. This password, after
entered, becomes encrypted in the configuration.
Enter enable secret:
% No defaulting allowed
Enter enable secret:
Already, there's something about Setup Mode that you might not like. This mode forces you to set an enable password and an enable secret password. As you continue in this mode, you'll see this mode ask you questions about every single interface on the router, even if you're not planning to use that interface. Using Setup Mode really does get quite old after a while, again in my opinion.
One of the most important things about Setup Mode is knowing how to get out of it without saving the configuration. One way is at the very end of this mode, where you can answer "no" to "Do you want to save this configuration?" I personally never make it that far! Instead of waiting until the end of Setup Mode, we can use the CTRL-C key combination to abort this mode and ignore the changes.
Configuration aborted, no changes made.
Press RETURN to get started!
Setup Mode is not a mode that CCNA and CCNP candidates get a great deal of practice with, but you will be tested on your knowledge about it both in the exam room and on the job. And once you start configuring a router with this mode, you'll be glad you know how to get out of it!
Friday, December 26, 2008
Passing Cisco's CCNA and CCNP Exams: Five Tips For Exam Day Success
As you get ready to pass the CCNA or CCNP exams, you can feel quite a bit of stress as you enter your last week of study. Let's take a look at a few ways to reduce that stress.
1. Do not stay up late cramming. The CCNA and CCNP are not exams you're going to pass by cramming. "Cramming" is a study technique best left behind in junior high school. The CCNA can't be passed by memorization - you've got to know how Cisco technologies work. That leads us to the second point...
2. Get lots of rest. By far, this is the most overlooked factor on exam day. The CCNA and CCNP exams are going to demand your best. You're going to be performing subnetting, binary and hex conversions, analyzing network diagrams for troubleshooting, and much more. You've got to be mentally sharp. You can add 100 points to your exam score just by showing up well-rested. And let's be realistic - if you don't know something at 11 PM the night before your exam, you're not going to learn it overnight. Get some sleep!
3. Get everything together the night before the exam. You don't want to be running around the house the morning of the exam looking for your keys. Make sure you have your keys and your ID the night before the exam.
4. Know where the testing center is. If you've never been to the center you'll be passing the CCNA in before, go there before the morning of the exam. Do not rely on Mapquest or a friend's directions. You don't want to be late for your exam.
5. Allow for traffic. Many CCNA and CCNP candidates prefer to take their exams in the morning. Again, if you haven't been to the exam center before, you should drive there during morning rush hour traffic before your exam date to make sure you have enough time to get there. You don't want to be sitting in traffic when you should be sitting in the exam room!
1. Do not stay up late cramming. The CCNA and CCNP are not exams you're going to pass by cramming. "Cramming" is a study technique best left behind in junior high school. The CCNA can't be passed by memorization - you've got to know how Cisco technologies work. That leads us to the second point...
2. Get lots of rest. By far, this is the most overlooked factor on exam day. The CCNA and CCNP exams are going to demand your best. You're going to be performing subnetting, binary and hex conversions, analyzing network diagrams for troubleshooting, and much more. You've got to be mentally sharp. You can add 100 points to your exam score just by showing up well-rested. And let's be realistic - if you don't know something at 11 PM the night before your exam, you're not going to learn it overnight. Get some sleep!
3. Get everything together the night before the exam. You don't want to be running around the house the morning of the exam looking for your keys. Make sure you have your keys and your ID the night before the exam.
4. Know where the testing center is. If you've never been to the center you'll be passing the CCNA in before, go there before the morning of the exam. Do not rely on Mapquest or a friend's directions. You don't want to be late for your exam.
5. Allow for traffic. Many CCNA and CCNP candidates prefer to take their exams in the morning. Again, if you haven't been to the exam center before, you should drive there during morning rush hour traffic before your exam date to make sure you have enough time to get there. You don't want to be sitting in traffic when you should be sitting in the exam room!
Microsoft Certification: Farewell To The MCSE
Microsoft is in the middle of a major push to overhaul its certification program. Last year, they announced the new Microsoft Certified Architect (MCA) certification, which is not a written exam but rather a practical exam that will be graded by a board of examiners. Just applying for the certification will require 10 years' experience in IT as well as three years of practical experience as a network architect.
For those of us not quite ready for that, Microsoft has announced that it's also going to revise other certifications. The MCSE that we've all come to know and love is going to be a thing of the past. In its place will be a series of specialization exams and IP Professional certification tracks.
If you're currently an MCSE or working it, don't worry, you have plenty of time to adapt to the new tracks. Microsoft's official word is that the new certification structure will be implemented when the next Windows server/client version is released. For those holding MCDBAs, your current certification will remain valid and you'll have a chance to upgrade to the new certification with SQL Server 2005.
Those of us who have been on the certification track for a while remember the outcry when Microsoft planned to phase out the much-maligned NT 4.0 certification in the move to Windows 2000. There was quite an outcry from many certified individuals who felt MS was being unreasonable in their timetable and planned lack of support for the 4.0 certification. Whether you agree with Microsoft's planned changes, I urge you to visit Microsoft's certification site regularly to keep up with these changes.
Whether you choose to pursue any of these new tracks is your decision, but you owe it to yourself and your career to know about the new tracks. Change is inevitable in IT and the IT certification world, and you must be aware of these changes!
For those of us not quite ready for that, Microsoft has announced that it's also going to revise other certifications. The MCSE that we've all come to know and love is going to be a thing of the past. In its place will be a series of specialization exams and IP Professional certification tracks.
If you're currently an MCSE or working it, don't worry, you have plenty of time to adapt to the new tracks. Microsoft's official word is that the new certification structure will be implemented when the next Windows server/client version is released. For those holding MCDBAs, your current certification will remain valid and you'll have a chance to upgrade to the new certification with SQL Server 2005.
Those of us who have been on the certification track for a while remember the outcry when Microsoft planned to phase out the much-maligned NT 4.0 certification in the move to Windows 2000. There was quite an outcry from many certified individuals who felt MS was being unreasonable in their timetable and planned lack of support for the 4.0 certification. Whether you agree with Microsoft's planned changes, I urge you to visit Microsoft's certification site regularly to keep up with these changes.
Whether you choose to pursue any of these new tracks is your decision, but you owe it to yourself and your career to know about the new tracks. Change is inevitable in IT and the IT certification world, and you must be aware of these changes!
How To Become a Cisco CCNP
Congratulations on your decision to earn your CCNP certification! As a CCIE, I can tell you that Cisco certifications are both financially and personally rewarding.
To earn your CCNP, you first have to earn your CCNA certification. Then you're faced with a decision - take the three-exam CCNP path, or the four-exam path? They're both quite demanding, so let's take a look at each path.
The four-exam CCNP path includes the Building Scalable Cisco Internetworks exam (BSCI), Building Cisco Multilayer Switched Networks exam (BCMSN), Building Cisco Remote Access Networks (BCRAN), and Cisco Internetwork Troubleshooting (CIT) exam.
The three-exam path combines the BSCI and BCMSN exams into a single exam, called the Composite exam.
I'm often asked what order I recommend taking the exams in. After earning your CCNA, I recommend you begin studying for the BSCI exam immediately. You will find the fundamentals you learned in your CCNA studies will help you a great deal with this exam. You're going to add to your CCNA knowledgebase quite a bit when it comes to OSPF and EIGRP, as well as being introduced to BGP.
I don't have a preference between the BCMSN and BCRAN exams, but I do recommend you take the CIT exam last. You'll be using all the skills you learned in the first three exams to pass the CIT. It's a very demanding exam, and it's a little hard to troubleshoot technologies that you haven't learned yet!
The CCNP is both financially and personally fulfilling. Once you complete your CCNA studies, take a little breather and then get started on your CCNP studies. The more you know, the more valuable you are in today's ever-changing IT job market.
To earn your CCNP, you first have to earn your CCNA certification. Then you're faced with a decision - take the three-exam CCNP path, or the four-exam path? They're both quite demanding, so let's take a look at each path.
The four-exam CCNP path includes the Building Scalable Cisco Internetworks exam (BSCI), Building Cisco Multilayer Switched Networks exam (BCMSN), Building Cisco Remote Access Networks (BCRAN), and Cisco Internetwork Troubleshooting (CIT) exam.
The three-exam path combines the BSCI and BCMSN exams into a single exam, called the Composite exam.
I'm often asked what order I recommend taking the exams in. After earning your CCNA, I recommend you begin studying for the BSCI exam immediately. You will find the fundamentals you learned in your CCNA studies will help you a great deal with this exam. You're going to add to your CCNA knowledgebase quite a bit when it comes to OSPF and EIGRP, as well as being introduced to BGP.
I don't have a preference between the BCMSN and BCRAN exams, but I do recommend you take the CIT exam last. You'll be using all the skills you learned in the first three exams to pass the CIT. It's a very demanding exam, and it's a little hard to troubleshoot technologies that you haven't learned yet!
The CCNP is both financially and personally fulfilling. Once you complete your CCNA studies, take a little breather and then get started on your CCNP studies. The more you know, the more valuable you are in today's ever-changing IT job market.
Four Important Commands For Your CCNA / CCNP Home Lab
More CCNA and CCNP candidates than ever before are putting together their own home practice labs. It's more affordable than it ever has been, and I receive emails daily from new CCNAs and CCNPs who say it's the best thing they could have done to improve their studies.
There are some commands you can configure on your lab routers that won't necessarily be on your CCNA or CCNP exams, but they will make life a lot easier for you. Let's take a look at just a few of these.
The command "no exec" is short, yet powerful. Occasionally you'll have what is referred to as a "rogue EXEC" process tie up a line, and you end up having to continually clear lines, which disrupts your practice. If you have an access server, I highly recommend you configure this command on your lines, as shown here:
ACCESS_SERVER(con)#line 1 8
ACCESS_SERVER(con)#no exec
From your CCNA studies, you know that the command "no ip domain-lookup" prevents a Cisco router from sending a broadcast to find a DNS server anytime you enter something that is not an IOS command - and that includes mistyped commands, which happens to all of us sooner or later. Make sure to run that command in global configuration mode on all your practice routers.
There are two commands I like to configure on the console line on all my practice routers and switches. The first is "exec-timeout 0 0", which prevents you from being kicked out of enable mode and back into user exec after a few minutes of inactivity. (This doesn't sound like much, but you'll get pretty tired of typing "enable" after a while.) The first zero refers to minutes, the second zero to seconds. Setting them both to zero disables the exec-timeout function.
The second command prevents the router from interrupting the command you're typing with a console message. If you've ever been in the middle of typing a router command and suddenly you're interrupted with a logging message, you know that can be pretty annoying. We don't want the router to not display the message, but we do want the router to wait until we're done entering data. The command to perform this is "logging synchronous".
R1(config)#line console 0
R1(config-line)#exec-timeout 0 0
R1(config-line)#logging synchronous
You won't see many of these commands on your exams, but after you configure them on your home lab devices, you'll wonder how you did without them!
There are some commands you can configure on your lab routers that won't necessarily be on your CCNA or CCNP exams, but they will make life a lot easier for you. Let's take a look at just a few of these.
The command "no exec" is short, yet powerful. Occasionally you'll have what is referred to as a "rogue EXEC" process tie up a line, and you end up having to continually clear lines, which disrupts your practice. If you have an access server, I highly recommend you configure this command on your lines, as shown here:
ACCESS_SERVER(con)#line 1 8
ACCESS_SERVER(con)#no exec
From your CCNA studies, you know that the command "no ip domain-lookup" prevents a Cisco router from sending a broadcast to find a DNS server anytime you enter something that is not an IOS command - and that includes mistyped commands, which happens to all of us sooner or later. Make sure to run that command in global configuration mode on all your practice routers.
There are two commands I like to configure on the console line on all my practice routers and switches. The first is "exec-timeout 0 0", which prevents you from being kicked out of enable mode and back into user exec after a few minutes of inactivity. (This doesn't sound like much, but you'll get pretty tired of typing "enable" after a while.) The first zero refers to minutes, the second zero to seconds. Setting them both to zero disables the exec-timeout function.
The second command prevents the router from interrupting the command you're typing with a console message. If you've ever been in the middle of typing a router command and suddenly you're interrupted with a logging message, you know that can be pretty annoying. We don't want the router to not display the message, but we do want the router to wait until we're done entering data. The command to perform this is "logging synchronous".
R1(config)#line console 0
R1(config-line)#exec-timeout 0 0
R1(config-line)#logging synchronous
You won't see many of these commands on your exams, but after you configure them on your home lab devices, you'll wonder how you did without them!
Computer Certification: Become A Utility Player
In baseball, a "utility player" is one who plays more than one position. These players are usually backups, but they have a job in the major leagues because of their value to the team; since they can play more than one position, they have that much more value to their employer.
Too often in IT, workers become either LAN or WAN engineers, knowing little if anything about the other side. Many LAN administrators I worked with knew little about routing and switching, while many WAN engineers I knew not only didn't know much about the LAN side of their network, but they didn't want to know anything about the servers!
In today's IT world, it's a bad idea to specialize in only one thing and not know how to do anything else. Not only does it limit your future career prospects, but it limits your current prospects as well. Employers don't want to hire someone and have them get up to speed on the job - they want someone who can walk right in and do the job. The more you know, the better your chance of getting a better job - or quickly being able to get another job if you were laid off tomorrow.
A term often heard on Wall Street is "diversification", meaning that investors should not invest heavily or totally in only one stock; if that stock plummets, they're in big trouble. Your career is the most important stock you will ever own, and you're 100% in charge of it. Diversify. If you're working primarily with servers, learn some routing and switching. If you know the routing protocols your company uses on its WAN, learn something about that protocol. (If you don't know the protocol, ask!)
While you’re adding these skills, get certified while you’re at it! Adding a CCNA, MCSE, or other computer certification looks great on your resume while signaling to employers that you’re constantly adding to your skills.
Adding more skills and knowledge to your IT skill set is always a good idea. Don't limit yourself to the technologies you work with every day. Make an investment in yourself and become a well-rounded network engineer. This will help you keep the job you have - and open doors in the future that might otherwise have remained closed.
Too often in IT, workers become either LAN or WAN engineers, knowing little if anything about the other side. Many LAN administrators I worked with knew little about routing and switching, while many WAN engineers I knew not only didn't know much about the LAN side of their network, but they didn't want to know anything about the servers!
In today's IT world, it's a bad idea to specialize in only one thing and not know how to do anything else. Not only does it limit your future career prospects, but it limits your current prospects as well. Employers don't want to hire someone and have them get up to speed on the job - they want someone who can walk right in and do the job. The more you know, the better your chance of getting a better job - or quickly being able to get another job if you were laid off tomorrow.
A term often heard on Wall Street is "diversification", meaning that investors should not invest heavily or totally in only one stock; if that stock plummets, they're in big trouble. Your career is the most important stock you will ever own, and you're 100% in charge of it. Diversify. If you're working primarily with servers, learn some routing and switching. If you know the routing protocols your company uses on its WAN, learn something about that protocol. (If you don't know the protocol, ask!)
While you’re adding these skills, get certified while you’re at it! Adding a CCNA, MCSE, or other computer certification looks great on your resume while signaling to employers that you’re constantly adding to your skills.
Adding more skills and knowledge to your IT skill set is always a good idea. Don't limit yourself to the technologies you work with every day. Make an investment in yourself and become a well-rounded network engineer. This will help you keep the job you have - and open doors in the future that might otherwise have remained closed.
Cisco Certification: Recertifying Your CCNA and CCNP
Once you get your CCNA and CCNP, you can't just rest on your accomplishment. You've got to continue to study and add to your skill set - and then prove to Cisco you've been doing just that by recertifying.
Recertification sounds like a pain, but it's actually one of the best things to ever happen to computer certification, and it helps your career as well. One trap many LAN and WAN personnel fall into is that they fail to keep up with changes in technology, and if they happen to be laid off or want to change jobs, they're unable to because they didn't keep their skill set up.
Cisco's recertification policies ensure that if you want to keep your CCNA, CCNP, or one of the other valuable Cisco certifications, you've got to take a recertification exam.
As of November 2005, to recertify as a CCNA, you need to pass either the current CCNA exam, ICND exam, or any 642 professional level or Cisco Qualified Specialist exam. (This does not include Sales Specialist exams.) Passing a CCIE written qualification exam also recertifies you as a CCNA. CCNAs are valid for three years.
For the CCNP, you need to pass the 642-891 Composite exam, a CCIE written qualification exam, or BOTH the BSCI and BCMSN exams (642-801 and 642-811, respectively.) CCNP certifications are valid for three years.
As you can see, you've got quite a few options either way. The one classic mistake you must not make is waiting too long to begin preparing for the exams, and give yourself a little leeway just in case you don't recertify the first time around. Once the deadline passes, your certification is gone, and in the case of the CCNP that means taking all the exams again.
As a professional, it's your responsibility to keep up with changes in the Cisco certification world, and this includes changes in the recertification program. Make a point of visiting the "Learning And Events" section of Cisco's website regularly to look for changes in the certification program. And while you're there, you just might see another cert that catches your eye!
Recertification sounds like a pain, but it's actually one of the best things to ever happen to computer certification, and it helps your career as well. One trap many LAN and WAN personnel fall into is that they fail to keep up with changes in technology, and if they happen to be laid off or want to change jobs, they're unable to because they didn't keep their skill set up.
Cisco's recertification policies ensure that if you want to keep your CCNA, CCNP, or one of the other valuable Cisco certifications, you've got to take a recertification exam.
As of November 2005, to recertify as a CCNA, you need to pass either the current CCNA exam, ICND exam, or any 642 professional level or Cisco Qualified Specialist exam. (This does not include Sales Specialist exams.) Passing a CCIE written qualification exam also recertifies you as a CCNA. CCNAs are valid for three years.
For the CCNP, you need to pass the 642-891 Composite exam, a CCIE written qualification exam, or BOTH the BSCI and BCMSN exams (642-801 and 642-811, respectively.) CCNP certifications are valid for three years.
As you can see, you've got quite a few options either way. The one classic mistake you must not make is waiting too long to begin preparing for the exams, and give yourself a little leeway just in case you don't recertify the first time around. Once the deadline passes, your certification is gone, and in the case of the CCNP that means taking all the exams again.
As a professional, it's your responsibility to keep up with changes in the Cisco certification world, and this includes changes in the recertification program. Make a point of visiting the "Learning And Events" section of Cisco's website regularly to look for changes in the certification program. And while you're there, you just might see another cert that catches your eye!
Thursday, December 25, 2008
Cisco Certification: In What Order Should You Take Your CCNP Exams ?
When you choose to pursue your Cisco Certified Network Professional certification, you've got some decisions to make right at the beginning. Cisco offers a three-exam path and a four-exam path, and you select the order in which you'll take and pass the exams.
While every CCNP candidate has to make their own decision, I'd like to share some thoughts based on my personal experience and the experiences of CCNPs worldwide.
The solid foundation of networking knowledge you built as a CCNA will help you a great deal on your BSCI (Building Scalable Cisco Internetworks, 642-801) exam. This is the most common exam to take first, and I'd recommend you do so as well. While there are some topics that will be new to you, such as BGP, many of the BSCI topics will be familiar to you from your CCNA studies.
The "middle" exams are the BCMSN (Building Cisco Multilayer Switched Networks, 642-811) and BCRAN (Building Cisco Remote Access Networks, 642-821). There is no real advantage in taking one of these before the other, although most candidates take the switching exam, then the remote access exam.
I do recommend you take the CIT (Cisco Internetwork Troubleshooting) exam last. This exam will demand you put into action the skills you have learned while earning your CCNA and passing the first three exams. Again, it's not written in stone and there are always exceptions, but CCNP candidates do seem to have more success on this exam when they take it last.
Should you choose the three-exam path, you'll be taking a Composite exam (642-891). This exam combines the BSCI and BCMSN exams, and it's best to take this one first. It builds nicely with your CCNA skills.
Again, I would take the BCRAN exam after the Composite, and t
he Troubleshooting exam last.
Whichever path you choose, you've chosen wisely in which certification to pursue. The CCNP is a true test of your networking skills, and when you make the decision to go after the CCIE, you'll be glad to have the solid foundation of networking skills your CCNA and CCNP studies gave you.
While every CCNP candidate has to make their own decision, I'd like to share some thoughts based on my personal experience and the experiences of CCNPs worldwide.
The solid foundation of networking knowledge you built as a CCNA will help you a great deal on your BSCI (Building Scalable Cisco Internetworks, 642-801) exam. This is the most common exam to take first, and I'd recommend you do so as well. While there are some topics that will be new to you, such as BGP, many of the BSCI topics will be familiar to you from your CCNA studies.
The "middle" exams are the BCMSN (Building Cisco Multilayer Switched Networks, 642-811) and BCRAN (Building Cisco Remote Access Networks, 642-821). There is no real advantage in taking one of these before the other, although most candidates take the switching exam, then the remote access exam.
I do recommend you take the CIT (Cisco Internetwork Troubleshooting) exam last. This exam will demand you put into action the skills you have learned while earning your CCNA and passing the first three exams. Again, it's not written in stone and there are always exceptions, but CCNP candidates do seem to have more success on this exam when they take it last.
Should you choose the three-exam path, you'll be taking a Composite exam (642-891). This exam combines the BSCI and BCMSN exams, and it's best to take this one first. It builds nicely with your CCNA skills.
Again, I would take the BCRAN exam after the Composite, and t
he Troubleshooting exam last.
Whichever path you choose, you've chosen wisely in which certification to pursue. The CCNP is a true test of your networking skills, and when you make the decision to go after the CCIE, you'll be glad to have the solid foundation of networking skills your CCNA and CCNP studies gave you.
Cisco CCNP Certification FAQ
To earn your CCNP, you've got to pass some very rigorous Cisco exams, and you also need to know the rules regarding this important certification. In this article, I'll answer some of the most commonly asked questions regarding the CCNP.
Q: What exams do I need to pass to get my CCNP?
A: You have two options, a three-exam path and a four-exam path. Currently, the four-exam path consists of rigorous exams on advanced routing techniques (BSCI), advanced switching (BCMSN), remote access methods (BCRAN), and advanced troubleshooting techniques (CIT). The three-exam path combines the BCMSN and BSCI exams into a single exam, the Composite exam.
Q: Do I have to take them in any order?
A: No, the order is up to the candidate. Most CCNP candidates take the BSCI exam first and the CIT exam last, but again this is up to the candidate.
Q: What else do I have to do to get the CCNP?
A: You must earn your CCNA before you can be CCNP certified (as well as passing the exams, of course).
Q: Is there a recertification requirement?
A: Cisco CCNP certifications are valid for three years. During that time, you must either pass the Composite exam, the BSCI and BCMSN exams, or pass any CCIE written exam.
Q: What if I don't recertify within the three-year period?
A: You must then meet whatever CCNP requirements there are at that time, from the beginning. It's easier to make sure you recertify!
Becoming CCNP certified is a great boost to your career and your confidence, and as with any Cisco certification, it's up to you to stay current with the CCNA and CCNP requirements. Visit the Career Certification section of Cisco's website regularly to learn about the program's requirements and changes.
Q: What exams do I need to pass to get my CCNP?
A: You have two options, a three-exam path and a four-exam path. Currently, the four-exam path consists of rigorous exams on advanced routing techniques (BSCI), advanced switching (BCMSN), remote access methods (BCRAN), and advanced troubleshooting techniques (CIT). The three-exam path combines the BCMSN and BSCI exams into a single exam, the Composite exam.
Q: Do I have to take them in any order?
A: No, the order is up to the candidate. Most CCNP candidates take the BSCI exam first and the CIT exam last, but again this is up to the candidate.
Q: What else do I have to do to get the CCNP?
A: You must earn your CCNA before you can be CCNP certified (as well as passing the exams, of course).
Q: Is there a recertification requirement?
A: Cisco CCNP certifications are valid for three years. During that time, you must either pass the Composite exam, the BSCI and BCMSN exams, or pass any CCIE written exam.
Q: What if I don't recertify within the three-year period?
A: You must then meet whatever CCNP requirements there are at that time, from the beginning. It's easier to make sure you recertify!
Becoming CCNP certified is a great boost to your career and your confidence, and as with any Cisco certification, it's up to you to stay current with the CCNA and CCNP requirements. Visit the Career Certification section of Cisco's website regularly to learn about the program's requirements and changes.
Cisco CCNP Certification: Using The BGP Command “Update-Source”
When you start preparing for your CCNP exam, particularly the BSCI exam, you're introduced to Border Gateway Protocol (BGP) configurations. BGP is unlike any protocol you learned during your CCNA studies, and even the similarities are a little bit different!
BGP forms neighbor relationships, much like EIGRP and OSPF do. The interesting thing with BGP is that potential neighbors, or "peers", do not need to be directly connected and can use their loopback interfaces to form the peer relationships.
It may well be to your advantage to use loopbacks to form peer relationships rather than the actual interface facing the potential neighbor. This can be done because BGP uses static neighbor statements rather than any kind of dynamic neighbor discovery process.
Consider a router that has two paths to a BGP speaker. The interfaces are numbered like this:
Router1: Serial0, 172.1.1.1 /24, Serial2, 179.1.1.1 /24, loopback0, 1.1.1.1 /32.
Router2: Serial0, 172.1.1.2/24, Serial2 179.1.1.2/24, loopback0, 2.2.2.2 /32.
We could configure Router1 like this:
router bgp 200
neighbor 172.1.1.2 remote-as 200
In this case, BGP would automatically use 172.1.1.1 as the source for the TCP connection that has to be set up with the neighbor before updates can be exchanged; this address is known as the best local address. However, if the remote peer's serial0 interface is shut down or goes down for another reason, the peer relationship would be lost even though Router2 is still available.
Instead of using one of the physical interfaces, we can use the loopbacks on each router to establish the TCP-based peer connection. The configurations would look like this:
Router1:
router bgp 200
neighbor 2.2.2.2 remote-as 200
neighbor 2.2.2.2 update-source loopback0
Router2:
router bgp 200
neighbor 1.1.1.1 remote-as 200
neighbor 1.1.1.1 update-source loopback0
In this case, losing one of the physical connections does not necessarily mean the BGP peering is lost; as long as the routers have a valid path to each other's loopback addresses, the BGP peer relationship will stay in place. And better yet, we avoid the dreaded “single point of failure
BGP forms neighbor relationships, much like EIGRP and OSPF do. The interesting thing with BGP is that potential neighbors, or "peers", do not need to be directly connected and can use their loopback interfaces to form the peer relationships.
It may well be to your advantage to use loopbacks to form peer relationships rather than the actual interface facing the potential neighbor. This can be done because BGP uses static neighbor statements rather than any kind of dynamic neighbor discovery process.
Consider a router that has two paths to a BGP speaker. The interfaces are numbered like this:
Router1: Serial0, 172.1.1.1 /24, Serial2, 179.1.1.1 /24, loopback0, 1.1.1.1 /32.
Router2: Serial0, 172.1.1.2/24, Serial2 179.1.1.2/24, loopback0, 2.2.2.2 /32.
We could configure Router1 like this:
router bgp 200
neighbor 172.1.1.2 remote-as 200
In this case, BGP would automatically use 172.1.1.1 as the source for the TCP connection that has to be set up with the neighbor before updates can be exchanged; this address is known as the best local address. However, if the remote peer's serial0 interface is shut down or goes down for another reason, the peer relationship would be lost even though Router2 is still available.
Instead of using one of the physical interfaces, we can use the loopbacks on each router to establish the TCP-based peer connection. The configurations would look like this:
Router1:
router bgp 200
neighbor 2.2.2.2 remote-as 200
neighbor 2.2.2.2 update-source loopback0
Router2:
router bgp 200
neighbor 1.1.1.1 remote-as 200
neighbor 1.1.1.1 update-source loopback0
In this case, losing one of the physical connections does not necessarily mean the BGP peering is lost; as long as the routers have a valid path to each other's loopback addresses, the BGP peer relationship will stay in place. And better yet, we avoid the dreaded “single point of failure
Cisco CCNP Certification: The BGP Weight Attribute
When you're studying for the CCNP certification, especially the BSCI exam, you must gain a solid understanding of BGP. BGP isn't just one of the biggest topics on the BSCI exam, it's one of the largest. BGP has a great many details that must be mastered for BSCI success, and those of you with one eye on the CCIE must learn the fundamentals of BGP now in order to build on those fundamentals at a later time.
Path attributes are a unique feature of BGP. With interior gateway protocols such as OSPF and EIGRP, administrative distance is used as a tiebreaker when two routes to the same destination had different next-hop IP addresses but the same prefix length. BGP uses path attributes to make this choice.
The first attribute considered by BGP is weight. Weight is a Cisco-proprietary BGP attribute, so if you're working in a multivendor environment you should work with another attribute to influence path selection.
The weight attribute is significant only to the router on which it is changed. If you set a higher weight for a particular route in order to give it preference (a higher weight is preferred over a lower one), that weight is not advertised to other routers.
BGP uses categories such as "transitive", "non-transitive", "mandatory", and "optional" to classify attributes. Since weight is a locally significant Cisco-proprietary attribute, it does not all into any of these categories.
The weight can be changed on a single route via a route-map, or it can be set for a different weight for all routes received from a given neighbor. To change the weight for all incoming routes, use the "weight" option with the neighbor command after forming the BGP peer relationships.
R2(config)#router bgp 100
R2(config-router)#neighbor 100.1.1.1 remote-as 10
R2(config-router)#neighbor 100.1.1.1 weight 200
Learning all of the BGP attributes, as well as when to use them, can seem an overwhelming task when you first start studying for your BSCI and CCNP exams. Break this task down into small parts, learn one attribute at a time, and soon you'll have the BGP attributes mastered.
Path attributes are a unique feature of BGP. With interior gateway protocols such as OSPF and EIGRP, administrative distance is used as a tiebreaker when two routes to the same destination had different next-hop IP addresses but the same prefix length. BGP uses path attributes to make this choice.
The first attribute considered by BGP is weight. Weight is a Cisco-proprietary BGP attribute, so if you're working in a multivendor environment you should work with another attribute to influence path selection.
The weight attribute is significant only to the router on which it is changed. If you set a higher weight for a particular route in order to give it preference (a higher weight is preferred over a lower one), that weight is not advertised to other routers.
BGP uses categories such as "transitive", "non-transitive", "mandatory", and "optional" to classify attributes. Since weight is a locally significant Cisco-proprietary attribute, it does not all into any of these categories.
The weight can be changed on a single route via a route-map, or it can be set for a different weight for all routes received from a given neighbor. To change the weight for all incoming routes, use the "weight" option with the neighbor command after forming the BGP peer relationships.
R2(config)#router bgp 100
R2(config-router)#neighbor 100.1.1.1 remote-as 10
R2(config-router)#neighbor 100.1.1.1 weight 200
Learning all of the BGP attributes, as well as when to use them, can seem an overwhelming task when you first start studying for your BSCI and CCNP exams. Break this task down into small parts, learn one attribute at a time, and soon you'll have the BGP attributes mastered.
Cisco CCNP Certification / BSCI Exam Tutorial: ISIS Hellos And Adjacencies
In my last ISIS tutorial, I mentioned that while ISIS and OSPF are both link state protocols, their actual operation differs greatly. To pass the BSCI exam and earn your CCNP, you'll need to know these differences! Today, we'll take a look at ISIS Hello types and the adjacency types that form through the use of these Hellos.
Hello packets have been mentioned several times with ISIS, and with good reason. Hello packets are the heartbeat of OSPF and ISIS when heartbeats are no longer heard from a neighbor, that adjacency will be dropped. A major difference between OSPF and ISIS is that OSPF has one type of Hello packet, where ISIS actually has three!
An ES Hello (ESH) is send by all End Systems, and all IS devices listen for this Hello. This is how a router (IS) discovers a host (ES).
An IS Hello (ISH) announces the presence of an IS. An IS Hello is sent by all IS devices, and End Systems listen for these hellos.
An IS-to-IS Hello (IIH) is used by an IS to discover other ISes and to form adjacencies with them.
An interesting side note: A router will send an IIH to another router on the link to form or maintain an adjacency, but it will still send an ISH as well in case there are end systems located on that segment.
ISIS and OSPF both create and maintain adjacencies with the Hello packet. Let's take a look at the rules regarding ISIS adjacencies as well as the adjacency types.
L1 and L2 Hellos are different messages, so an L1 router must exchange Hellos with another L1 router to form an adjacency, just as L2 routers form adjacencies with L2 routers. L1 routers can only form an adjacency with an L2 router if one of the two routers involved is actually an L1/L2 router.
L1 routers must be in the same area in order to form an adjacency. The Hello timers, as well as the MTU, must match between the interfaces used to form the adjacency.
That's a lot of L1, L2, and L1/L2, isn't it? Let's review the adjacencies each router type can form:
L1: Can form adjacency with any L1 in the same area and any L1/L2 in the same area.
L2: Can form adjacency with any L2 in any area, and with an L1/L2 in any area.
L1/L2: Can form adjacency with any L1 in the same area, L1/L2 in any area, and L2 in any area.
Knowing the similarities and differences regarding ISIS and OSPF is vital for CCNP exam success. Take your time, master the fundamentals, and before long the magic letters “CCNP” are behind your name and on your resume!
Hello packets have been mentioned several times with ISIS, and with good reason. Hello packets are the heartbeat of OSPF and ISIS when heartbeats are no longer heard from a neighbor, that adjacency will be dropped. A major difference between OSPF and ISIS is that OSPF has one type of Hello packet, where ISIS actually has three!
An ES Hello (ESH) is send by all End Systems, and all IS devices listen for this Hello. This is how a router (IS) discovers a host (ES).
An IS Hello (ISH) announces the presence of an IS. An IS Hello is sent by all IS devices, and End Systems listen for these hellos.
An IS-to-IS Hello (IIH) is used by an IS to discover other ISes and to form adjacencies with them.
An interesting side note: A router will send an IIH to another router on the link to form or maintain an adjacency, but it will still send an ISH as well in case there are end systems located on that segment.
ISIS and OSPF both create and maintain adjacencies with the Hello packet. Let's take a look at the rules regarding ISIS adjacencies as well as the adjacency types.
L1 and L2 Hellos are different messages, so an L1 router must exchange Hellos with another L1 router to form an adjacency, just as L2 routers form adjacencies with L2 routers. L1 routers can only form an adjacency with an L2 router if one of the two routers involved is actually an L1/L2 router.
L1 routers must be in the same area in order to form an adjacency. The Hello timers, as well as the MTU, must match between the interfaces used to form the adjacency.
That's a lot of L1, L2, and L1/L2, isn't it? Let's review the adjacencies each router type can form:
L1: Can form adjacency with any L1 in the same area and any L1/L2 in the same area.
L2: Can form adjacency with any L2 in any area, and with an L1/L2 in any area.
L1/L2: Can form adjacency with any L1 in the same area, L1/L2 in any area, and L2 in any area.
Knowing the similarities and differences regarding ISIS and OSPF is vital for CCNP exam success. Take your time, master the fundamentals, and before long the magic letters “CCNP” are behind your name and on your resume!
Cisco CCNP Certification / BSCI Exam Tutorial: Floating Static Routes
Passing the BSCI exam and earning your CCNP certification demands that you add greatly to the networking skills foundation you created when you studied for your CCNA certification. You learned quite a bit about static routing and default static routing when you passed the CCNA test, and it does seem like that should be all you need to know about static routing, right?
One thing you'll learn as you continue to earn Cisco certifications is that there's always something else to learn! You may have heard the term "floating static route", which does suggest some interesting mental pictures. "Floating"? Floating on what?
In a way, a floating static route is "floating" in your routing table. A floating static route is a route that will be used only if routes for the same destination but with a lower administrative distance are removed from the table. For example, you could be using an OSPF-discovered route as your primary route to a given destination, and the floating static route would serve as a backup route that would be used only if the OSPF route leaves the routing table.
Now, how can that happen? After all, OSPF has an administrative distance of 110 and static routes have ADs of one or zero, depending on whether it's configured with a next-hop IP address or a local exit interface. One way or the other, 1 and 0 are still less than 110!
When you want to configure a floating static route, you must assign the route an AD higher than that of the primary route. In this case, we've got to create a static route with an AD higher than 110. We do this by using the "distance" option at the end of the "ip route" command.
R1(config)#ip route 110.1.1.0 255.255.255.0 172.12.123.1 ?
<1-255> Distance metric for this route
name Specify name of the next hop
permanent permanent route
tag Set tag for this route
R1(config)#ip route 110.1.1.0 255.255.255.0 172.12.123.1 111
The number entered at the very end of the "ip route" command is the AD of that route. If there is an OSPF route for 110.1.1.0 /24, that will be the primary route, and the floating static route will not be used unless the OSPF route is taken out of the routing table.
Floating static routes aren't just a good thing to know for the BSCI exam and your CCNP certification pursuit - they're very practical in the real world as well.
One thing you'll learn as you continue to earn Cisco certifications is that there's always something else to learn! You may have heard the term "floating static route", which does suggest some interesting mental pictures. "Floating"? Floating on what?
In a way, a floating static route is "floating" in your routing table. A floating static route is a route that will be used only if routes for the same destination but with a lower administrative distance are removed from the table. For example, you could be using an OSPF-discovered route as your primary route to a given destination, and the floating static route would serve as a backup route that would be used only if the OSPF route leaves the routing table.
Now, how can that happen? After all, OSPF has an administrative distance of 110 and static routes have ADs of one or zero, depending on whether it's configured with a next-hop IP address or a local exit interface. One way or the other, 1 and 0 are still less than 110!
When you want to configure a floating static route, you must assign the route an AD higher than that of the primary route. In this case, we've got to create a static route with an AD higher than 110. We do this by using the "distance" option at the end of the "ip route" command.
R1(config)#ip route 110.1.1.0 255.255.255.0 172.12.123.1 ?
<1-255> Distance metric for this route
name Specify name of the next hop
permanent permanent route
tag Set tag for this route
R1(config)#ip route 110.1.1.0 255.255.255.0 172.12.123.1 111
The number entered at the very end of the "ip route" command is the AD of that route. If there is an OSPF route for 110.1.1.0 /24, that will be the primary route, and the floating static route will not be used unless the OSPF route is taken out of the routing table.
Floating static routes aren't just a good thing to know for the BSCI exam and your CCNP certification pursuit - they're very practical in the real world as well.
Cisco CCNP Certification / BSCI Exam Tutorial: An Introduction To BGP
When you're studying for the BSCI exam on the way to earning your CCNP certification, it's safe to say that BGP is like nothing you’ve studied to this point. BGP is an external routing protocol used primarily by Internet Service Providers (ISPs). Unless you work for an ISP today or in the future, you may have little or no prior exposure to BGP. Understanding BGP is a great addition to your skill set – and you have to know the basics well to pass the BSCI exam.
Note that I said “the basics”. BGP is a very complex protocol, and when you pursue your CCIE, you’ll see what I’m talking about. As with all things Cisco, though, when broken down into smaller pieces, BGP becomes quite understandable. You will need to know the basics of BGP as presented in this chapter to pass your BSCI exam – so let’s get started.
BGP Defined:
“An Internet protocol that enables groups of routers (called autonomous systems) to share routing information so that efficient, loop-free routes can be established. BGP is commonly used within and between Internet Service Providers (ISPs).”
There are a couple of terms in there that apply to the protocols you’ve mastered so far in your studies. The term “autonomous system” applies to IGRP and EIGRP as well as BGP; you’ll be indicating a BGP AS in your configurations just as you did with IGRP and EIGRP. And we’re always looking for efficient, loop-free routes, right? As it did with IGRP and EIGRP, "autonomous system" simply refers to a group of routers that is managed by a single administrative body. An autonomous system will use an Interior Gateway Protocol (IGP) such as OSPF or EIGRP to route packets inside the AS; outside the AS, an Exterior Gateway Protocol (EGP) such as BGP will be used.
BGP shares some characteristics with some routing protocols you’ve already studied. BGP supports VLSM, summarization, and CIDR. Like EIGRP, BGP will send full updates when two routers initially become neighbors and will send only partial updates after that. BGP does create and maintain neighbor relationships before exchanging routes, and keepalives are sent to keep this relationship alive.
BGP has some major differences from the IGPs we’ve studied to this point. You’ll hear BGP referred to as a path-vector protocol. As opposed to distance-vector protocols that exchange relatively simple information about available routes, BGP routers will exchange extensive information about networks to allow the routers to make more intelligent routing decisions. This additional BGP path information comes in the form of attributes, and these path attributes are contained in the updates sent by BGP routers. Attributes themselves are broken up into two classes, well-known and optional.
BGP also keeps a routing table separate from the IP routing table.
We'll take a look at BGP attributes in future BSCI tutorials. In the meantime, keep studying!
Note that I said “the basics”. BGP is a very complex protocol, and when you pursue your CCIE, you’ll see what I’m talking about. As with all things Cisco, though, when broken down into smaller pieces, BGP becomes quite understandable. You will need to know the basics of BGP as presented in this chapter to pass your BSCI exam – so let’s get started.
BGP Defined:
“An Internet protocol that enables groups of routers (called autonomous systems) to share routing information so that efficient, loop-free routes can be established. BGP is commonly used within and between Internet Service Providers (ISPs).”
There are a couple of terms in there that apply to the protocols you’ve mastered so far in your studies. The term “autonomous system” applies to IGRP and EIGRP as well as BGP; you’ll be indicating a BGP AS in your configurations just as you did with IGRP and EIGRP. And we’re always looking for efficient, loop-free routes, right? As it did with IGRP and EIGRP, "autonomous system" simply refers to a group of routers that is managed by a single administrative body. An autonomous system will use an Interior Gateway Protocol (IGP) such as OSPF or EIGRP to route packets inside the AS; outside the AS, an Exterior Gateway Protocol (EGP) such as BGP will be used.
BGP shares some characteristics with some routing protocols you’ve already studied. BGP supports VLSM, summarization, and CIDR. Like EIGRP, BGP will send full updates when two routers initially become neighbors and will send only partial updates after that. BGP does create and maintain neighbor relationships before exchanging routes, and keepalives are sent to keep this relationship alive.
BGP has some major differences from the IGPs we’ve studied to this point. You’ll hear BGP referred to as a path-vector protocol. As opposed to distance-vector protocols that exchange relatively simple information about available routes, BGP routers will exchange extensive information about networks to allow the routers to make more intelligent routing decisions. This additional BGP path information comes in the form of attributes, and these path attributes are contained in the updates sent by BGP routers. Attributes themselves are broken up into two classes, well-known and optional.
BGP also keeps a routing table separate from the IP routing table.
We'll take a look at BGP attributes in future BSCI tutorials. In the meantime, keep studying!
Cisco CCNP Certification / BSCI Exam Tutorial: Comparing IRDP And HSRP
To pass the BSCI exam, you need to know the difference between IRDP and HSRP. While they have the same basic function, the operation and configuration of each are totally different.
The aim of both is to allow hosts to quickly discover a standby router when the primary router fails. IRDP is commonly used by Windows DHCP clients and several Unix variations, but you do see it in Cisco routers as well. IRDP is defined in RFC 1256.
IRDP routers will multicast Hello messages that host devices hear. If a host hears from more than one IRDP router, it will choose one as its primary and will start using the other router if the primary it's chosen goes down.
HSRP is a Cisco-proprietary protocol that is designed for quick cutover to a secondary router if the primary fails, but the host devices don't "see" either the primary or secondary router. The hosts use a virtual router as their default gateway. This virtual router has its own IP and MAC address! All the while, the router chosen as the primary is actually the one doing the routing. If the primary router goes down, the secondary router quickly takes over with no major interruption to network services.
The HSRP routers communicate by multicasting updates to 224.0.0.2, and its through these hellos that the HSRP routers decide which router is primary and which is secondary. HSRP is defined in RFC 2281.
The configuration of each of these will be covered in a future tutorial. In the meantime, I urge you to read the RFCs mentioned in this article, and visit www.cisco.com/univercd to read about the configurations and options available for both of these vital protocols.
The aim of both is to allow hosts to quickly discover a standby router when the primary router fails. IRDP is commonly used by Windows DHCP clients and several Unix variations, but you do see it in Cisco routers as well. IRDP is defined in RFC 1256.
IRDP routers will multicast Hello messages that host devices hear. If a host hears from more than one IRDP router, it will choose one as its primary and will start using the other router if the primary it's chosen goes down.
HSRP is a Cisco-proprietary protocol that is designed for quick cutover to a secondary router if the primary fails, but the host devices don't "see" either the primary or secondary router. The hosts use a virtual router as their default gateway. This virtual router has its own IP and MAC address! All the while, the router chosen as the primary is actually the one doing the routing. If the primary router goes down, the secondary router quickly takes over with no major interruption to network services.
The HSRP routers communicate by multicasting updates to 224.0.0.2, and its through these hellos that the HSRP routers decide which router is primary and which is secondary. HSRP is defined in RFC 2281.
The configuration of each of these will be covered in a future tutorial. In the meantime, I urge you to read the RFCs mentioned in this article, and visit www.cisco.com/univercd to read about the configurations and options available for both of these vital protocols.
Cisco CCNP / BSCI Tutorial: The Role Of The OSPF ASBR
To pass the BSCI exam and earn your CCNP certification, you've got to master the (many) details of OSPF. You might have thought there were quite a few OSPF details in your CCNA studies, but you'll now build on that foundation on the way to earning your CCNP.
One such detail is the role of the Autonomous System Border Router (ASBR) in OSPF. The name itself raises some eyebrows, since you learned in your CCNA studies that OSPF doesn't use autonomous systems! Just as an OSPF Area Border Router borders multiple OSPF areas, the ASBR borders the entire OSPF domain and another source of routes. This can be another dynamic routing protocol, or directly connected networks that are not being advertised into OSPF by the network command.
Let's say we have a router running both OSPF and RIP version 2. By default, the RIP process will not contain any OSPF-discovered routes, and vice versa. The two separate routing processes are just that - separate. If we want the other OSPF routers to know about the RIP routes, route redistribution must be configured. When the RIP routes are redistributed into OSPF, that router is then an ASBR.
In the below example, RIP subnets have been redistributed into OSPF. A seed metric is not necessary when redistributing routes into OSPF. The command "show ip ospf" confirms that this router is now an ASBR.
R1(config)#router ospf 1
R1(config-router)#redistribute rip subnets
R1#show ip ospf
Routing Process "ospf 1" with ID 1.1.1.1
Supports only single TOS(TOS0) routes
Supports opaque LSA
It is an autonomous system boundary router
The ASBR can also perform route summarization on the routes being injected into OSPF with the summary-address command. (To configure OSPF inter-area summarization, use the area range command.) By mastering route summarization and route redistribution, you're well on your way to passing the BSCI exam and earning your CCNP certification!
One such detail is the role of the Autonomous System Border Router (ASBR) in OSPF. The name itself raises some eyebrows, since you learned in your CCNA studies that OSPF doesn't use autonomous systems! Just as an OSPF Area Border Router borders multiple OSPF areas, the ASBR borders the entire OSPF domain and another source of routes. This can be another dynamic routing protocol, or directly connected networks that are not being advertised into OSPF by the network command.
Let's say we have a router running both OSPF and RIP version 2. By default, the RIP process will not contain any OSPF-discovered routes, and vice versa. The two separate routing processes are just that - separate. If we want the other OSPF routers to know about the RIP routes, route redistribution must be configured. When the RIP routes are redistributed into OSPF, that router is then an ASBR.
In the below example, RIP subnets have been redistributed into OSPF. A seed metric is not necessary when redistributing routes into OSPF. The command "show ip ospf" confirms that this router is now an ASBR.
R1(config)#router ospf 1
R1(config-router)#redistribute rip subnets
R1#show ip ospf
Routing Process "ospf 1" with ID 1.1.1.1
Supports only single TOS(TOS0) routes
Supports opaque LSA
It is an autonomous system boundary router
The ASBR can also perform route summarization on the routes being injected into OSPF with the summary-address command. (To configure OSPF inter-area summarization, use the area range command.) By mastering route summarization and route redistribution, you're well on your way to passing the BSCI exam and earning your CCNP certification!
Cisco CCNP / BSCI Tutorial: The BGP Attribute NEXT_HOP
When you're studying for the BSCI exam on the way to earning your CCNP certification, you've got to master the use of BGP attributes. These attributes allow you to manipulate the path or paths that BGP will use to reach a given destination when multiple paths to that destination exist.
In this free BGP tutorial, we're going to take a look at the NEXT_HOP attribute. You may be thinking "hey, how complicated can this attribute be?" It's not very complicated at all, but this being Cisco, there's got to be at least one unusual detail about it, right?
The NEXT_HOP attribute is simple enough - this attribute indicates the next-hop IP address that should be taken to reach a destination. In the following example, R1 is a hub router and R2 and R3 are spokes. All three routers are in BGP AS 100, with R1 having a peer relationship with both R2 and R3. There is no BGP peering between R2 and R3.
R3 is advertising the network 33.3.0.0 /24 via BGP, and the value of the next-hop attribute on R1 is the IP address on R3 that is used in the peer relationship, 172.12.123.3.
The issue with the next-hop attribute comes in when the route is advertised to BGP peers. If R3 were in a separate AS from R1 and R2, R1 would then advertise the route to R2 with the next-hop attribute set to 172.12.123.3. When a BGP speaker advertises a route to iBGP peers that was originally learned from an eBGP peer, the next-hop value is retained.
Here, all three routers are in AS 100. What will the next-hop attribute be set to when R1 advertises the route to its iBGP neighbor R2?
R2#show ip bgp
< no output >
There will be no next-hop attribute for the route on R2, because the route will not appear on R2. By default, a BGP speaker will not advertise a route to iBGP neighbors if the route was first learned from another iBGP neighbor.
Luckily for us, there are several ways around this rule. The most common is the use of route reflectors, and we'll look at RRs in a future free BGP tutorial.
In this free BGP tutorial, we're going to take a look at the NEXT_HOP attribute. You may be thinking "hey, how complicated can this attribute be?" It's not very complicated at all, but this being Cisco, there's got to be at least one unusual detail about it, right?
The NEXT_HOP attribute is simple enough - this attribute indicates the next-hop IP address that should be taken to reach a destination. In the following example, R1 is a hub router and R2 and R3 are spokes. All three routers are in BGP AS 100, with R1 having a peer relationship with both R2 and R3. There is no BGP peering between R2 and R3.
R3 is advertising the network 33.3.0.0 /24 via BGP, and the value of the next-hop attribute on R1 is the IP address on R3 that is used in the peer relationship, 172.12.123.3.
The issue with the next-hop attribute comes in when the route is advertised to BGP peers. If R3 were in a separate AS from R1 and R2, R1 would then advertise the route to R2 with the next-hop attribute set to 172.12.123.3. When a BGP speaker advertises a route to iBGP peers that was originally learned from an eBGP peer, the next-hop value is retained.
Here, all three routers are in AS 100. What will the next-hop attribute be set to when R1 advertises the route to its iBGP neighbor R2?
R2#show ip bgp
< no output >
There will be no next-hop attribute for the route on R2, because the route will not appear on R2. By default, a BGP speaker will not advertise a route to iBGP neighbors if the route was first learned from another iBGP neighbor.
Luckily for us, there are several ways around this rule. The most common is the use of route reflectors, and we'll look at RRs in a future free BGP tutorial.
Cisco CCNP / BSCI Tutorial: Comparing OSPF and ISIS Hellos
While studying to pass the BSCI exam and preparing to earn your CCNP certification, you'll quickly notice that while OSPF and ISIS are both link-state protocols, there are a lot of differences between the two. One major difference is the way the two protocols handle hello packets.
Hello packets are imperative to keeping OSPF and ISIS adjacencies alive. Since they are both link-state protocols, neither of them will send updates at any specified time. Hello packets are the only method by which routers running OSPF and ISIS can see that a neighboring router is still available.
OSPF gives us some great options when it comes to keeping routing table size down via the use of stub and total stub areas, but to OSPF, a hello packet is a hello packet. ISIS routers are capable of sending two different types of hellos - Level 1 and Level 2.
ISIS routers are classified as Level 1 (L1), Level 2 (L2), and Level 1-2 (L1-L2). By default, Cisco routers are L1-L2 routers; this means that every ISIS-enabled interface will send out both L1 and L2 hellos.
If one of the interfaces is forming only an L1 or L2 adjacency, there's no reason to send out hellos for the other adjacency type. For example, if R1 is forming an L1 adjacency with R2 via its ethernet0 interface, there is no reason to allow the router to transmit L2 hellos. To hardcode a router interface to send only L1 or L2 hellos, use the isis circuit-type command.
R1(config)#interface ethernet0
R1(config-if)#isis circuit-type level-1
Note: To configure this interface to send only L2 hellos, the full command is "isis circuit-type level-2-only", not just "level-2".
This configuration would prevent L2 hellos from being transmitted out ethernet0. While this does save router resources and prevents unnecessary bandwidth usage, there is also no way an L2 adjacency can be formed - so double-check your network topology before using this command!
Hello packets are imperative to keeping OSPF and ISIS adjacencies alive. Since they are both link-state protocols, neither of them will send updates at any specified time. Hello packets are the only method by which routers running OSPF and ISIS can see that a neighboring router is still available.
OSPF gives us some great options when it comes to keeping routing table size down via the use of stub and total stub areas, but to OSPF, a hello packet is a hello packet. ISIS routers are capable of sending two different types of hellos - Level 1 and Level 2.
ISIS routers are classified as Level 1 (L1), Level 2 (L2), and Level 1-2 (L1-L2). By default, Cisco routers are L1-L2 routers; this means that every ISIS-enabled interface will send out both L1 and L2 hellos.
If one of the interfaces is forming only an L1 or L2 adjacency, there's no reason to send out hellos for the other adjacency type. For example, if R1 is forming an L1 adjacency with R2 via its ethernet0 interface, there is no reason to allow the router to transmit L2 hellos. To hardcode a router interface to send only L1 or L2 hellos, use the isis circuit-type command.
R1(config)#interface ethernet0
R1(config-if)#isis circuit-type level-1
Note: To configure this interface to send only L2 hellos, the full command is "isis circuit-type level-2-only", not just "level-2".
This configuration would prevent L2 hellos from being transmitted out ethernet0. While this does save router resources and prevents unnecessary bandwidth usage, there is also no way an L2 adjacency can be formed - so double-check your network topology before using this command!
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