Configuring The Way To Advertise/Receive Routing Information; Configuration Prerequisites - H3C S5600 SERIES Operation Manual

To do...
Allow routers that belong to
non-directly connected
networks to establish EBGP
connections.
To configure basic functions of BGP peer group, you need to create the BGP peer group first. Refer
to section "Configuring BGP Peer
In order for route updating packets being sent even if problems occur on interfaces, you can
configure the source interfaces of route update packets as a loopback interface.
Normally, EBGP peers are connected through directly connected physical links. If no such link
exists, you need to use the peer ebgp-max-hop command to allow the peers to establish
multiple-hop TCP connections between them. If loopback interfaces are used to establish
connections between EBGP peers, the peer ebgp-max-hop command is unnecessary.
Note the following:
It is required to specify for a BGP router a router ID, a 32-bit unsigned integer and the unique
identifier of the router in the AS.
You can specify a router ID manually. If not, the system selects an IP address as the router ID. The
selection sequence is: If loopback interface addresses are available, the last configured loopback
interface IP address is used as the router ID; otherwise, the first configured interface IP address is
used as the router ID. It is recommended to specify a loopback interface address as the router ID to
enhance network reliability.
Router IDs can be re-selected. A re-selected router ID takes effect only after the BGP process is
restarted.

Configuring the Way to Advertise/Receive Routing Information

Configuration Prerequisites

Enable the basic BGP functions before configuring the way to advertise/receive BGP routing
information.
Make sure the following information is available when you configure the way to advertise/receive BGP
routing information.
The summarization mode, and the summary route.
Access list number
Filtering direction (advertising/receiving) and the route policies to be adopted.
Route dampening settings, such as half-life and the thresholds.
Use the command...
peer group-name
ebgp-max-hop
[ hop-count ]
Group" for information about creating a BGP peer group.
5-16
Remarks
Optional
By default, routers that belong to
two non-directly connected
networks cannot establish EBGP
connections.
You can configure the maximum
hops of EBGP connection by
specifying the hop-count argument.