CCNP Recertification

Posted on Friday, 23rd April 2004 by sean

While I can’t find anything in the exam outline dealing specifically with administrative distance, it is such an important thing I’m going to cover it anyway. My guess is that it falls under List the key information routers needs to route data Cisco IOS supports many different routing protocols. It is possible that multiple protocols [...]

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Posted on Tuesday, 6th April 2004 by sean

EIGRP, the Enhanced Interior Routing Protocol, is a Cisco proprietary protocol, meaning other vendors don’t support it. While this may turn you off right away (and it did for me until I got into it), it is a good protocol, fairly scalable, and converges quickly. The objectives associated with it are: Describe the features and [...]

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Posted on Sunday, 28th March 2004 by sean

After more research, and talking with a couple of people, I’ve found out that R1 and R2 will never see each other’s routes over an L2 adjacency, only over an L1 (which they can’t have, since they’re in separate areas) The only way around this appears to give them connectivity, either by a GRE tunnel, [...]

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Posted on Saturday, 27th March 2004 by sean

If you’re following along with my IS-IS example, it seems it’s a bit more complex than I thought. I brought up R2 and R1 stopped working. So far, I’ve set the priority on R3 to 99 so it becomes the DIS which lets R1 and R2 see all routes except each other’s. Going to pull [...]

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Posted on Friday, 26th March 2004 by sean

To finish up with IS-IS for now, I’m going to go through the set up of a four router, three area IS-IS network that uses a hub and spoke frame relay network. Here is a drawing of the network: The goal is to simply have all the addresses, including the loopbacks, appear in the routing [...]

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Posted on Thursday, 25th March 2004 by sean

I don’t want to spend much more time on IS-IS so that I can get to other things. From what I can tell, the level of knowledge required is not as deep as it is for OSPF, EIGRP, and BGP. As mentioned earlier, a router configured as L1-L2 will form an adjacency twice, once for [...]

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Posted on Tuesday, 23rd March 2004 by sean

Since I’ve been having so much fun with IS-IS recently, I thought I’d look closer at the hello process whereby neighbours form an adjacency. I took two routers, connected over an Ethernet interface, and turned on IS-IS. r0: interface Loopback99 ip address 1.1.1.1 255.255.255.255 ip router isis interface Ethernet0 ip address 10.50.0.1 255.255.255.0 ip router [...]

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Posted on Monday, 22nd March 2004 by sean

I’ve been going over some of the basics behind the OSI protocols, it’s finally time to look at the operation of IS-IS, and compare it to OSPF The IS-IS protocol uses four types of packets: Link State Packets (LSP) – distributes the link state information Hello PDUs – For adjacencies Partial Sequence Number (PSNP) – [...]

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Posted on Friday, 19th March 2004 by sean

In the IS-IS Intro I presented a few links for the IS-IS protocol. Before I can proceed to the configuration/verification of IS-IS (ie the good stuff), I have to go over the underlying OSI protocols. IS-IS started life out as the routing protocol for CLNP, or the Connectionless Network Protocol. Integrated IS-IS was later made [...]

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Posted on Thursday, 18th March 2004 by sean

IS-IS, or Intermediate System to Intermediate System is a new addition to the CCNP path. It is therefore likely that most people looking at the recertification will not have dealt with it. The objectives associated with IS-IS are: Explain basic OSI terminology and network layer protocols used in OSI Identify similarities and differences between Integrated [...]

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