Configuring the next_hop attribute – H3C Technologies H3C S12500-X Series Switches User Manual

Page 230

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not belong to the confederation, BGP does not compare it with other routes. As a result, the first route

becomes the optimal route.
To enable MED comparison for routes from confederation peers (IPv4):

Step Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Enter BGP view or BGP-VPN
instance view.

Enter BGP view:

bgp as-number

Enter BGP-VPN instance view:

a.

bgp as-number

b.

ip vpn-instance

vpn-instance-name

N/A

3.

Enter BGP IPv4 unicast
address family view or

BGP-VPN IPv4 unicast

address family view.

address-family ipv4 [ unicast ] N/A

4.

Enable MED comparison for
routes from confederation

peers.

bestroute med-confederation

By default, this feature is disabled.

To enable MED comparison for routes from confederation peers (IPv6):

Step Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Enter BGP view.

bgp as-number

N/A

3.

Enter BGP IPv6 unicast

address family view.

address-family ipv6 [ unicast ] N/A

4.

Enable MED comparison for
routes from confederation

peers.

bestroute med-confederation

By default, this feature is disabled.

324B

Configuring the NEXT_HOP attribute

By default, a BGP router does not set itself as the next hop for routes advertised to an IBGP peer or peer

group. In some cases, however, you must configure the advertising router as the next hop to make sure
the BGP peer can find the correct next hop.
For example, as shown in

1152H

Figure 56

, Router A and Router B establish an EBGP neighbor relationship, and

Router B and Router C establish an IBGP neighbor relationship. If Router C has no route destined for IP

address 1.1.1.1/24, you must configure Router B to set itself 3.1.1.1/24 as the next hop for the network
2.1.1.1/24 advertised to Router C.

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