The peer route-server-client command enables the route server function on a device and specifies an EBGP peer as its client.
The peer route-server-client disable command disables the route server function on a device and cancels the client configuration.
The undo peer route-server-client command cancels the route server function and client configuration.
The undo peer route-server-client disable command restores the default configuration and takes effect only when the peer route-server-client disable command is run.
By default, the route server function is not enabled on a device, and no EBGP peer is configured as its client.
Usage Scenario
In some scenarios on the live network, to achieve network traffic interworking, EBGP full-mesh connections may be required. However, establishing full-mesh connections among Routers that function as ASBRs is costly and places high requirements on the performance of the Routers, which adversely affects the network topology and Router expansion. The route server function is similar to the RR function in IBGP scenarios and allows Routers to advertise routes to their clients (ASBR Routers) without changing route attributes, such as AS_Path, Nexthop, and MED. With the route server function, EBGP full-mesh connections are not required among the ASBR Routers, which reduces network resource consumption.
Precautions
The configuration of a peer takes precedence over that of the peer group to which the peer belongs.
After the route server function is enabled for a specified EBGP peer on the local device, messages sent from the local device to the EBGP peer do not carry the local AS number. Therefore, you need to run the peer check-first-as disable command on the peer device to disable the peer from checking the first AS number in the AS_Path attribute in the Update message sent from the local end. Otherwise, the peer end cannot accept the routes sent from the local end. The command is mutually exclusive with the peer label-route-capability, confederation id, confederation peer-as, or confederation nonstandard command.