BGP Lab Exercise 2 ------------------ 1. We're now going to extend the BGP network to something a little more realistic. You should start by meeting the rest of the routers in your group. 2. Find Write down the AS numbers of the network(s) that you are connecting to: Upstream AS Number: Your AS Number: Do this for every peer that you have to setup. It is handy to have this information. Which of these are iBGP and which of these are eBGP peers? 3. Identify and configure the iBGP peers. Remember that these need to be configured as a full-mesh. Configure the full mesh and confirm that you can see the "clients" from each router. At the end of the exercise, each PC should be pingable from the other PCs. 4. By now you should know that your IGP (in this case, OSPF) should be well configured to get your iBGP to work. 4.1 Make sure that you, as a group, understand the dependency that iBGP has on your IGP. 4.2 Ensure that you have all your OSPF neighbors and all the relevant routers visible via OSPF. How many neighbors will you expect to see? How many other routers? 5. You were taught that iBGP is done between loopback addresses. 5.1 Why is it important that we do this? 5.2 What does the next-hop-self command do, and why do you need it here (if at all)? 5.3 How do we know how to get to the next hop address (the loopback) of our iBGP peers? 6. Check the BGP process for IPv4 using "sh ip bgp" and sub commands to see what prefixes you are receiving from your neighboring AS. For IPv6, remember that the syntax is "sh bgp ipv6 unicast” and sub commands. Note that "sh bgp ipv4 u” will also work to show you the state of the IPv4 BGP table. 7. What routes do you see? What paths are available? Describe what you see in the space below: 8. What *new* routes do you see? What paths are available? Describe what you see in the space below: 9. We are now at the stage where we are talking BGP with our upstream ISP and iBGP with the neighboring router in our locality. We are using both IPv4 and IPv6 for this neighbor relationships. Note that this is the common way that ISPs configure IPv4 and IPv6 neighbors - whatever is done with IPv4 is repeated with IPv6.