BGP

CCIE Challenge 3: MPLS L3VPN

This challenge is split up in four parts. Make sure you achieve the desired goals, even after multiple reboots of the routers in your topology. The initial config files can be downloaded here. General restrictions: You are not allowed to modify any IP address on any interface You are not allowed to introduce any new interfaces Part 1: IGP. Configure OSPF area 0 on the links between R7, R8, R11 and R12 Lo0 is part of OSPF area 0 Configure EIGRP as 100 on the links between R8, R9, R10, R13 and R12 Make sure the EIGRP process supports delay measured in picoseconds Lo0 on R10 and R13 should be D EX routes Lo0 on R9 should be part of EIGRP as 100 as a native EIGRP route Configure RIP on the links between R7, R5, R6, R8 and R9 Redistribute between all processes on all possible routers Part 2: iBGP.

CCIE Challenge 2: Troubleshoot Ticket 1

This #CCIEChallenge is a troubleshooting ticket for your pleasure. Depending on where you are in your CCIE prep you should be able to fix this ticket in 10 minutes. It would be comparable to a 3 or 4 point ticket. The config files can be downloaded here. R1 and R4 should be able to ping each other. Match the following output. R1 should always select its path through R3, even when R3 has suffered a failure and has returned to operations.

CCIE Challenge 1: DMVPN FVRF local breakout

So, this is the first CCIEChallenge created by me. You need to achieve the following to pass the challenge: In the topology, please ignore R15. It has no role in this assignment. The initial config files can be downloaded here Set up a DMVPN between R14 (hub), R10 and R11 (spokes) This DMVPN needs to use the default route the routers have received from R12. The links between R12 and the other routers are part of the INTERNET VRF, the DMVPN should be member of the global routing table.

BGP route reflector challenge answer

This will be a short post. This post is just to supply a somewhat detailed answer to a tweet I sent out earlier this evening. When you have 3 iBGP routers. One of them is a route reflector. The other two are clients. If the cluster-id of the route reflector is the same as the router-id of one of the clients. What will happen when the client receives an update from the route reflector?

BGP peer group vs. BGP templates

Most people who have done a little more than basic BGP configuration have encountered BGP peer groups. These groups help you manage larger configurations, or at least that is what you’ve been told. BGP peer groups are not designed to manage large BGP configurations. That’s what BGP templates are for. But if that’s the case what are the peer groups used for? And what’s the difference between the two? This post will answer exactly those questions.

OSPF / BGP path selection challenge

Today I’ve created a nice path selection challenge for everybody. Let’s start with the topology: IP addressing is simple. The subnets used are 10.0.xx.y/24 where xx are the numbers of the two routers on the link (lowest router first). Y is the router number. The situation is as follows: R2 has an eBGP peering with R1. It receives tge default route from R1. R2 advertises this default route to R3 R2 and R3 also form an OSPF network with area 0 R2 forms an OSPF NSSA area 50 with R4 R2 redistributes the connected route to R1 into OSPF R3 forms an OSPF NSSA area 50 with R5 R4 redistributes OSPF NSSA 50 into BGP (including NSSA external routes) R5 redistributes (i)BGP routes into OSPF So the questions are:

BGP Conditional Advertisements

One of the seemingly complicated things to do in BGP is conditional advertisements. This can be used to apply policy to routes and only advertise specific routes when you (don’t) have another route. For example, you only advertise a default route when you have specific routes from a peer. Another example is when you’re connected to two ISPs, but you prefer data to traverse just one of the two links. Maybe because one link is more expensive than the other or less reliable.