I have a question for everyone. I'm using a variety of vendors' workbooks to work on labs and have run across something that has been bothering me. Not so much a question about any lab but more of a general thing. If the lab you are working on doesn't expressly forbid a solution, is it okay to use it? More specifically the use of tunnels to solve some issues.
Here is an example of what I mean. You have two routers that you are told to set up as EBGP peers. Router 1 (R1) is in AS 100 and router 2 (R2) is in AS 200. Let's assume that they are connected to a common vlan using f0/1. R1 has an ip of 10.0.0.1/24 with a secondary ip of 10.1.1.1/24. R1 has an ip of 10.1.1.2/24 with a secondary ip of 10.0.0.2/24. You are told to set up the peering without using the secondary addresses. R1 int f0/1 ip address 10.0.0.1 255.255.255.0 ip address 10.1.1.1 255.255.255.0 secondary R2 int f0/1 ip address 10.1.1.2 255.255.255.0 ip address 10.0.0.2 255.255.255.0 secondary One way to do this would be to set your neighbor statements within BGP to point to each of the primary addresses. In order to get the peer to come up you will need to add "update-source f0/1" for one of the neighbor statements. R1 router bgp 100 neighbor 10.1.1.2 remote-as 200 neighbor 10.1.1.2 update-source f0/1 R2 router bgp 200 neighbor 10.0.0.1 remote-as 100 This works well. Another way would be create a tunnel, assign it some addresses and set the peering relationship through it. While not the best solution, it would work. Probably not a good example, but it one that comes to mind. So I guess the gist of my question is this, if for some reason you can't get something to work for you and for what ever reason you can't come up with another solution. In the example above, say for whatever reason you just didn't think of using update-source on one of the ends and the tunnel was the only way you could get it to work, would this be acceptable in the lab. While obviously not the optimal solution, it does work and it doesn't violate any of the rules of the scenario. Is it cool to use something like this in the lab? Like I said, not a big deal, just something that's been bugging me. I have had a couple of instances where I have noticed that you could come up with a similar soluton. Hopefully hs makes sense. Thanks. Cody _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
