H3C Technologies H3C SecPath F1000-E - Manual (Page 485)

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To enable the comparison of MED of routes from confederation peers:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view. bgp as-number N/A
3. Enable the comparison of MED
of routes from confederation
peers.
bestroute med-confederation
Optional.
Not enabled by default.
NOTE:
The MED attributes of routes from confederation peers are not compared if their AS-path attributes contain
AS numbers that do not belong to the confederation, such as these three routes: AS-path attributes of them
are 65006 65009, 65007 65009 and 65008 65009, and MED values of them are 2, 3, and 1. Because
the third route contains an AS number that does not belong to the confederation, the first route becomes
the optimal route.
Configuring the next hop attribute
By default, when advertising routes to an IBGP peer/peer group, a BGP router does not set itself as the
next hop. However, to ensure a BGP peer can find the correct next hop in some cases, you need to
configure the router as the next hop for routes sent to the peer.
For example, as shown in
Figure 286 , Router A and Router B establish an EBGP neighbor relationship,
and Router B and Router C establish an IBGP neighbor relationship. When Router B advertises a network
learned from Router A to Router C, if Router C has no route to IP address 1.1.1.1/24, you need to configure
Router B to set itself as the next hop (3.1.1.1/24) for the route to be sent to Router C.
Figure 286 Next hop attribute configuration
If a BGP router has two peers on a common broadcast network, it does not set itself as the next hop for
routes sent to an EBGP peer by default. As shown in Figure 287 , Router A and Router B establish an EBGP
neighbor relationship, and Router B and Router C establish an IBGP neighbor relationship. They are on
the same broadcast network 1.1.1.0/24. When Router B sends EBGP routes to Router A, it does not set
itself as the next hop by default. However, you can configure Router B to set it as the nexthop (1.1.1.2/24)
for routes sent to Router A by using the peer next-hop-local command as needed.
Figure 287 Next hop attribute configuration