3com S7906E Manuel De Montage

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*>i 1.0.0.0 193.1.1.1 50 100 0 100i

* i 192.1.1.1 100 100 0 100i

You can find route 1.0.0.0/8 is the optimal.

Configure different local preferences on Switch B and C for route 1.0.0.0/8, making Switch D give

priority to the route from Switch C.

# Define an ACL numbered 2000 on Router C, permitting route 1.0.0.0/8.

[SwitchC] acl number 2000

[SwitchC-acl-basic-2000] rule permit source 1.0.0.0 0.255.255.255

[SwitchC-acl-basic-2000] quit

# Configure a routing policy named localpref on Switch C, setting the local preference of route 1.0.0.0/8

to 200 (the default is 100).

[SwitchC] route-policy localpref permit node 10

[SwitchC-route-policy] if-match acl 2000

[SwitchC-route-policy] apply local-preference 200

[SwitchC-route-policy] quit

# Apply routing policy localpref to routes from peer 193.1.1.1.

[SwitchC] bgp 200

[SwitchC-bgp] peer 193.1.1.1 route-policy localpref import

[SwitchC-bgp] quit

# Display the routing table on Switch D.

[SwitchD] display bgp routing-table

Total Number of Routes: 2

BGP Local router ID is 194.1.1.1

Status codes: * - valid, > - best, d - damped,

h - history, i - internal, s - suppressed, S - Stale

Origin : i - IGP, e - EGP, ? - incomplete

Network NextHop MED LocPrf PrefVal Path/Ogn

*>i 1.0.0.0 193.1.1.1 0 200 0 100i

* i 192.1.1.1 0 100 0 100i

You can find route 1.0.0.0/8 from Switch D to Switch C is the optimal.

Configuring BFD for BGP

Network requirements

As shown in

Switch A and Switch B are interconnected through a Layer 2 switch. BFD is enabled on the

connected interfaces. BGP is enabled on the switches that are reachable to each other at the

network layer.

When the link between Switch A and Switch B fails, BFD can quickly detect the failure and notify

BGP of the failure.