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How do I configure iBGP on my border routers?
Hi,
We run VRRP on the inside of our Juniper border routers, and I've had a static 0.0.0.0/0 254 route pointing from each router to the other in the case that the BGP sessions on the primary router go down (say the fibre gets cut), but the router itself stays up (meaning it's still the VRRP master and receiving the traffic with nowhere to go).
This lets traffic flow into the vrrp master (router 0) and then through to router 1, then out to the world.
This works ok.
I would like to swap this to iBGP instead of static routes, but because our upstream advertise us a 0.0.0.0/0 route in the bgp feed (along with lots of other routes) its causing problems.
Basically router 1 receives the bgp feed containing it's 0.0.0.0 - 111.x.x.x route which comes in at a 100 local pref, and it also has a 0.0.0.0 - 192.168.1.2 (local interface) 254 pref configured locally.
Local config:
I then use iBGP to advertise the 0.0.0.0 route to router0, but because the upstream's default route is a lower pref, it will advertise that (0.0.0.0 111.x.x.x), instead of my intended one (0.0.0.0 - 192.168.1.2).
This means that if router0 drops its bgp session with the upstream, it will have a route from router1 saying 0.0.0.0 111.x.x.x which is useless as it can't reach that 111.x.x.x due to the connection drop.
I've tired this:
But that doesn't work.
How do I force router1 to send 0.0.0.0 192.168.1.2 instead of 0.0.0.0 111.x.x.x.x?
Thanks,
We run VRRP on the inside of our Juniper border routers, and I've had a static 0.0.0.0/0 254 route pointing from each router to the other in the case that the BGP sessions on the primary router go down (say the fibre gets cut), but the router itself stays up (meaning it's still the VRRP master and receiving the traffic with nowhere to go).
This lets traffic flow into the vrrp master (router 0) and then through to router 1, then out to the world.
This works ok.
I would like to swap this to iBGP instead of static routes, but because our upstream advertise us a 0.0.0.0/0 route in the bgp feed (along with lots of other routes) its causing problems.
Basically router 1 receives the bgp feed containing it's 0.0.0.0 - 111.x.x.x route which comes in at a 100 local pref, and it also has a 0.0.0.0 - 192.168.1.2 (local interface) 254 pref configured locally.
Local config:
route 0.0.0.0/0 {
next-hop 192.168.1.2;
preference 254;
}
I then use iBGP to advertise the 0.0.0.0 route to router0, but because the upstream's default route is a lower pref, it will advertise that (0.0.0.0 111.x.x.x), instead of my intended one (0.0.0.0 - 192.168.1.2).
This means that if router0 drops its bgp session with the upstream, it will have a route from router1 saying 0.0.0.0 111.x.x.x which is useless as it can't reach that 111.x.x.x due to the connection drop.
I've tired this:
policy-statement exportdefault {
term default {
from {
route-filter 0.0.0.0/0 exact {
next-hop 192.168.1.2;
}
}
then accept;
}
term else {
then reject;
}
}
But that doesn't work.
How do I force router1 to send 0.0.0.0 192.168.1.2 instead of 0.0.0.0 111.x.x.x.x?
Thanks,
That is a very common problem. In Cisco, there's a neighbor command which is "next-hop-self." This tells the router to advertise itself as the next hop to an iBGP neighbor which is not the default, as you discovered.
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You should be sending default via your IGP not via iBGP.
harbor235 ;}