[Xorp-users] Help with iBGP configuration

[CouchSurfer]

Hi all,

I have two linux boxes running xorp. I want them to share routes,
possibly using some form of ibgp, but have so far failed. I am
wondering if anyone can help. Everything below are ipv4 only, and I am
using xorp v 1.6 (2009/01/08).

I have two routers, iA and iB. Each of them is connected to the same
external AS but to different eBGP peers eA_1, eA_2 and eB_1, eB_2.
Each connection with eBGP peers are established using a different
interface.

The eBGP peers eA_1 and eB_1advertise the same unicast destinations
but via different routes (eA_1 and eB_1 respectively). Additionally,
eA_2 and eB_2 are pim neighbours with different rendex-vous points
eRP_a, eRP_b that know about different multicast groups with different
source ip addresses.

When run individually, both iA and iB can establish eBGP peerships
properly and hosts having them as default gateways can join and leave
multicast groups and establish unicast connections to foreign servers
OK.

Now, I want both of these routers to share both unicast and multicast
routes learnt from their respective eBGP peers so that a hosts with
with router as default gateway can join and leave multicast groups and
establish unicast connections to foreign servers OK. I am not a
networking expert so I am a little confused what additional protocols
I may need to set up iBGP nor what type of policy I would need to set
up or where they should be applied.

Using the following pasted configuration, when iA is on and is a
default gateway for a host, i found the following:
- iA ONLY is on - the host can establish unicast connection with
foreigh servers and join goups known by eRP_a;
- iB ONLY is on - the host canNOT establish unicast connection with
foreigh servers but can join goups known by eRP_b;
- iA started BEFORE iB - the host can establish unicast connection
with foreigh servers but can join goups known by eRP_b;
- iA started AFTER iB - the host can establish unicast connection with
foreigh servers but can join goups known by eRP_b;
- In any case, whenever iB is on, all multicast group queries seem to
only go through iB.

Any help will be gratefully appreciated. Thanks in advance

========================================================================================
Config snipet. At present, to create iBGP peership, I do (with x, y =
1, 2, x!=y)

protocols {
    bgp {
        bgp-id: ip_of_x
        confederation {
            identifies: "my_as"
        }
        peer "ip_of_y" {
            local-ip: "ip_of_x"
            as: my_as
            next-hop: ip_of_x
            ipv4-unicast: true
            ipv4-multiicast: false
            import: "import-from-ibgp"
            export: "export-from-ibgp"
        }
        /* info about eBPG peers */
    }
    opsf4 {
        router-id: ip_of_x
        area 0.0.0.0 {
            interface "eth0" {
                vif "eth0" {
                    address ip_of_x
                }
            }
        }
    }
    /* additional protocols: igmp, pimsm4, fib2mrib */
}
policy {
    policy-statement "export-to-ibgp" {
        term 0 {
            from {
                protocol: "ospf4"
            }
            then {
                med: 100
                accept {
                }
            }
        }
        term 1 {
            from {
                protocol: "connected"
            }
            then {
                med: 100
                accept {
                }
            }
        }
        term 2 {
            from {
                protocol: "bgp"
            }
            then {
                med: 100
                accept {
                }
            }
        }
    }
    policy-statement "import-from-ibgp" {
        term 0 {
            from {
            }
            then {
                localpref: 100
                accept {
                }
            }
        }
    }
}
================================================================================