2eW4ZRB

}
Please note that it is important to configure the physical interface address of the remote
ASBR node. Don’t use the loopback address, otherwise the TED will contain inconsistent
information and it will be impossible to correctly forward packets. We will see this better later
on.
3.5 IBGP Configuration
The ASBRs are IBGP IP unicast (AFI=1, SAFI=1) route reflectors for the PE routers within AS
65536 and AS 65538. The following is the configuration for the ASBR1 in AS 65536:
user@asbr1# show protocols bgp group IBGP-DOWN
type internal;
local-address 192.168.36.5;
family inet {
unicast;
}
export PL-IBGP-DOWN-EXP;
cluster 192.168.36.5;
neighbor 192.168.36.21;
neighbor 192.168.36.22;
The policy PL-IBGP-DOWN-EXP controls the PE loopbacks from the remote AS 65538 that
are exported to the local PE inside AS 65536:
[edit policy-options]
user@asbr1# show
policy-statement PL-IBGP-DOWN-EXP {
term REMOTE-LOOPBACKS {
from {
protocol bgp;
community CM-REMOTE-LOOPBACKS;
}
then {
next-hop self;
accept;
}
}
[other terms]
}
community CM-REMOTE-LOOPBACKS members 38:1000;
It is fundamental that the PE loopback addresses are exchanged via BGP between the
remote PE in different ASs.
3.6 EBGP on the Inter-AS Links
EBGP IP unicast (AFI=1, SAFI=1) is used to peer different ASBRs in neighboring ASs. The
peering is done using the inter-AS link addresses:
[edit protocols bgp]
user@asbr1# show
group EBGP {
type external;
family inet {
unicast;
}
export PL-EBGP-EXP;
peer-as 65537;
neighbor 172.16.37.2;
}
The policy PL-EBGP-EXP is used to advertise the local PE router loopback addresses to the
remote ASs:
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