We're currently in the testing phase of migrating our internally static-routed network to an iBGP-routed network. At the core we're using redundant 6509s. I'm configuring these to be the iBGP hubs in which all other enterprise routers peer to and must route though. Unfortunately it appears though that the routes passed down to the BGP peers are actually causing the nodes to routes directly to eachother rather than through the core. We're designing this as hub-and-spoke with the 2 6509s acting as route reflectors. Below is the configuration from one of the 6509s:
router bgp 65000
timers bgp 2 5
neighbor 192.168.1.2 remote-as 65000
neighbor 192.168.1.2 description A_Node
neighbor 192.168.1.2 route-reflector-client
neighbor 192.168.1.2 next-hop-self
neighbor 192.168.1.5 remote-as 65000
neighbor 192.168.1.5 description 2nd_Node
When the 192.168.1.2 node receives it's routes to networks behind the 192.168.1.5 router from the 6509 the next hop address shows as 192.168.1.5, rather than the 6509. From my understanding by attaching "next-hop-self" to the neighbor all routes should have a next hop of the 6509. Am I misunderstanding it's usage or how to configure this? Any help would be appreciated!
Next-hop-self on the RR will only apply to eBGP learnt routes. The RR will not change the BGP next-hop for iBGP learnt route.
This is by design and in compliance with RFC1966. Here's an excerpt from section 8:
"In some implementations, modification of the BGP path attribute, NEXT_HOP is possible. For example, there could be a need for a RR to modify NEXT_HOP for EBGP learned routes sent to its internal peers. However, it must not be possible for an RR to set on reflected IBGP routes as this breaks the basic principle of Route Reflection and will result in potential black holeing of traffic."
Hope this helps,
Harold Ritter Sr. Technical Leader CCIE 4168 (R&S, SP) firstname.lastname@example.org México móvil: +52 1 55 8312 4915 Cisco México Paseo de la Reforma 222 Piso 19 Cuauhtémoc, Juárez Ciudad de México, 06600 México
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.