DFS

To pass the BSCI exam and earn your CCNP, you’ve got to know ISIS inside and out.  There are many similarities between ISIS and OSPF, but one major difference is that ISIS has three different types of routers – Level 1 (L1), Level 2 (L2), and L1/L2.

L1 routers are contained in a single area, and are connected to other areas by an L1/L2 router.  The L1 uses the L1/L2 router as a default gateway to reach destinations contained in other areas, much like an OSPF stub router uses the ABR as a default gateway.

L1 routers have no specific routing table entries regarding any destination outside their own area; they will use an L1/L2 router as a default gateway to reach any external networks.  ISIS L1 routers in the same area must synchronize their databases with each other.

Just as we have L1 routers, we also have L2 routers.  Anytime we’re routing between areas (inter-area routing), an L2 or L1/L2 router must be involved.  All L2 routers will have synchronized databases as well.

Both L1 and L2 routers send out their own hellos.  As with OSPF, hello packets allow ISIS routers to form adjacencies.  The key difference here is that L1 routers send out L1 hellos, and L2 routers send out L2 hellos.  If you have an L1 router and an L2 router on the same link, they will not form an adjacency.

An ISIS router can act as an L1 and an L2 router at the same time; these routers are L1/L2 routers.  An L1/L2 router can have neighbors in separate ISIS areas.  The L1/L2 router will have two separate databases, though – one for L1 routes and another for L2 routes.  L1/L2 is the default setting for Cisco routers running ISIS.  The L1/L2 router is the router that makes it possible for an L1 router to send data to another area.

• l2 router
• ISIS ABR router
• L1 router L2 router L1/L2 router

Ask a CCNA candidate how they’re preparing for exam day, and you’ll get different answers. Different books, different websites, different practice exams.

One trend I’ve noticed is that some candidates answer the question by reeling off the number and names of the practice exams they’ve purchased. Basically, the candidate is studying by taking a lot of practice exams. And in some cases, I mean a lot of them.

The intent of this article isn’t to slam practice exams. I do want to address this trend among Cisco certification candidates of purchasing as many practice exams as they can find, attempting to pass the CCNA exam by “brute forcing” it, as one Cisco employee recently said.

I have nothing against practice exams. I sell flash cards that serve as a practice exam, if that’s the way the candidate wants to use them. However, you can’t be dependent on them to pass your exams. As I tell students every day, “When you’re in front of a rack of routers, there is no A, B, C, and D choice. You’ve got to know what you’re doing.”

If practice exams are a candidate’s primary tool for exam preparation, though, they’ll most likely be disappointed on exam day. The current Cisco CCNA exams are designed to weed out those who have memorized a chart or two there is a premium not only on knowledge, but the ability to apply that knowledge. Just taking one practice exam after the other will not develop this skill.

Simulators are fine to a certain extent as well, but don’t become dependent on them. The simulators I’ve seen don’t really let you make mistakes in your configuration, and it’s when you have to fix your own mistakes that you truly learn what’s going on.

Keep the long-range view when preparing for your CCNA exams. You’re not just studying for exam day you’re laying the groundwork for a successful career. The study you do for your CCNA exam will be some of the most important study you ever do, since all the work you do for future certifications like the CCNP (and yes, the CCIE!) are based on the foundation you’re building today.

Make it a solid foundation. Stick to a well-rounded study plan, using books, practice exams, and routing equipment, and you’re on your way to success in the Cisco field.

I hardly have to tell you how important voice technologies are in today’s networks; what we all need to keep in mind to maximize our career potential is how important knowing voice is going to be tomorrow.

We’ve always got to look forward in IT, both in our work and out studies. Cisco, always the pioneer in technical certifications, now offers a Cisco Certified Voice Professional certification that is gaining a lot of attention from IT professionals looking to add to their skills and their resume.

Cisco’s CCVP track is a rigorous five-exam track that requires you to earn your CCNA (Cisco Certified Network Associate) certification before getting started. The five exams cover a myriad of topics – they’re not giving this one away! Here are the exam numbers and codes you’ll need to know to register for the exams:

642-642 Quality Of Service (QOS)

642-432 Cisco Voice Over IP (CVOICE)

642-425 IP Telephony Troubleshooting (IPTT)

642-444 Cisco IP Telephony (CIPT)

642-452 Cisco Voice Gateways (GWGK)

Many newly-minted CCNAs wonder if they should pursue this or the Security Professional certification immediately after getting their CCNA. I recommend that a new CCNA pursue and achieve the CCNP before going after these more-specialized certifications. While it is not required by Cisco, the routing and switching knowledge your will acquire on your way to the CCNP will be invaluable to your career as well as being helpful with your CCVP pursuits.

Besides, these certifications won’t be going anywhere soon. Think of how valuable you will be with a CCNP, CCVP, and CCSP!

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.

• bgp weight
• bgp weight attribute
• bgp wight

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!

• ccnplogging synchronous
• the most important commands in ccna