(Optional) Configuring BGP-EVPN Route Reflection on an ASBR
When multiple PEs exist in the ASs, you can configure an ASBR as an RR to lower configuration complexity.
Context
In inter-AS EVPN Option B mode, if multiple PEs exist in an AS, you can configure an ASBR as an RR to reduce the number of MP-IBGP connections needed between PEs. Configuring an ASBR as an RR will burden the ASBR. Therefore, it is recommended that a high-performance device be used as the ASBR. ASBR1 is configured as an RR so that PE1 and PE2 do not need to set up an MP-IBGP peer relationship.
Procedure
- Run system-view
The ASBR1 system view is displayed.
- Run bgp { as-number-plain | as-number-dot }
The BGP view is displayed.
- Run l2vpn-family evpn
The BGP-EVPN address family view is displayed.
- Run peer peerIpv4Addr reflect-client
ASBR1 is configured as an RR, and the PE is configured as a client. If you need to configure multiple PEs as clients, repeatedly run this command.
- Run peer peerIpv4Addr next-hop-local
The ASBR is configured to change the next hop address of a route to the device's own IP address before the device advertises the route to an IBGP peer.
- (Optional) If the clients are fully meshed, run the undo reflect between-clients command to disable route reflection between the clients through RRs.
- (Optional) Run rr-filter extended-list-number
A reflection policy is configured for the RR.
- (Optional) Run reflect change-path-attribute
The RR is enabled to modify BGP route attributes using an export policy.
After the reflect change-path-attribute command is run on the RR:
- Under BGP-EVPN address family view, peer route-policy export command takes precedence over the peer next-hop-invariable command.
- Under BGP-EVPN address family view, peer next-hop-local command takes precedence over the peer route-policy export command.
- Run commit
The configuration is committed.