3Com 8807 Configuration Manual page 496

496 C 46: MBGP M
HAPTER
Configuring the MED
Value for an AS
Comparing MED Values
from Different AS
Neighbor Paths
Configuring Local
Preference
Configuring MBGP Timer
Configuring MBGP Peer
(Group)
E C
ULTICAST XTENSION ONFIGURATION
The MED configured in BGP view is valid for both unicast and multicast.
For the details of this configuration, refer to "BGP Configuration" of the Routing
Protocol part.
Do not use this configuration unless you are sure that different ASs adopt the
same IGP and route selection method. The configuration in BGP view works both
in unicast and multicast.
For the details of this configuration, refer to "BGP Configuration" of the Routing
Protocol part.
Different local preference can be configured as a reference of the MBGP route
selection. When an MBGP router gets routes with the same destination but
different next hops through different neighbors, it will choose the route with the
highest local preference.
The configuration works both in unicast and multicast.
For the details of this configuration, refer to "BGP Configuration" of the Routing
Protocol part.
After a router establishes MBGP connection with a peer, it sends Keepalive
messages to the peer periodically to check for the smooth connection. If the
router does not receive a single Keepalive message or any other kind of message
from the peer within the defined connection Holdtime, it will think the MBGP
connection broken and exit, and will process the routing information received
through this connection as appropriate. Therefore, the Keepalive message sending
interval and MBGP connection Holdtime are two parameters of great importance
in MBGP mechanism.
The configuration works both in unicast and multicast.
For the details of this configuration, refer to "BGP Configuration" of the Routing
Protocol part.
The use of MBGP peer groups is to simplify configuration. When configuring
MBGP peers, you can create and configure a peer group in BGP view, and then
add the peers into the group, since all peers in a group have the same
configuration with the group. Then, enable this peer group in IPv4 multicast
sub-address family view and add peers to this peer group to create MBGP peers
and an MBGP peer group. In conclusion, to create MBGP peers/peer groups, you
must configure them successfully in BGP view first.
c
CAUTION: Configure the peer group under the guide of technical support
engineers.
Creating a peer group with members
To configure a MBGP peer (group), configure a peer group in BGP view and add
peers to this peer group. For details, refer to "BGP Configuration" in the Routing
Protocol part.