3com S7906E Installationsanweisungen
1-9
To do…
Use the command…
Remarks
Configure the
default MED
value
default MED
value
default med med-value
Optional
0 by default.
Enable the
comparison of the
MED of routes
from different ASs
comparison of the
MED of routes
from different ASs
compare-different-as-med
Optional
Not enabled by default
Enable the
comparison of the
MED of routes
from each AS
comparison of the
MED of routes
from each AS
bestroute compare-med
Optional
Not enabled by default
Configure
the MED
attribute
the MED
attribute
Enable the
comparison of the
MED of routes
from
confederation
peers
comparison of the
MED of routes
from
confederation
peers
bestroute med-confederation
Optional
Not enabled by default
Configuring the Next Hop Attribute
You can use the peer next-hop-local command to specify the local router as the next hop of routes
sent to a MBGP iBGP peer/peer group. If load balancing is configured, the router specifies itself as the
next hop of route advertisements to the multicast iBGP peer/peer group regardless of whether the peer
next-hop-local command is configured.
In a “third party next hop" network, that is, the local router has two multicast eBGP peers in a broadcast
network, the router does not specify itself as the next hop of routing information sent to the eBGP peers
unless the peer next-hop-local command is configured.
Follow these steps to specify the router as the next hop of routes sent to a peer/peer group:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter BGP view
bgp as-number
—
Enter IPv4 MBGP address family
view
view
ipv4-family multicast
—
Specify the router as the next hop
of routes sent to a peer/peer
group
of routes sent to a peer/peer
group
peer { group-name | ip-address }
next-hop-local
next-hop-local
Optional
By default, the next hop
of routes sent to a MBGP
eBGP peer/peer group is
the advertising router,
while that of routes sent
to a MBGP iBGP
peer/peer group is not.
of routes sent to a MBGP
eBGP peer/peer group is
the advertising router,
while that of routes sent
to a MBGP iBGP
peer/peer group is not.
Configuring the AS-PATH Attribute
In general, MBGP checks whether the AS_PATH attribute of a route from a peer contains the local AS
number. If yes, it discards the route to avoid routing loops.