Bgp Community Configuration - 3Com S7906E Configuration Manual

The route 9.1.1.0/24 has two next hops 3.1.1.1 and 3.1.2.1, both of which are marked with a
greater-than sign (>), indicating they are the best routes.
Using the display ip routing-table command, you can find two routes to 9.1.1.0/24: one with next
hop 3.1.1.1 and outbound interface VLAN-interface 200, the other with next hop 3.1.2.1 and
outbound interface VLAN-interface 300.

BGP Community Configuration

Network requirements
As shown in the following figure, Switch B establishes eBGP connections with Switch A and C.
Configure No_Export community attribute on Switch A to make routes from AS 10 not advertised by AS
20 to any other AS.
Figure 1-23 Network diagram for BGP community configuration
Configuration procedure
1) Configure IP addresses for interfaces (omitted)
2) Configure eBGP
# Configure Switch A.
<SwitchA> system-view
[SwitchA] bgp 10
[SwitchA-bgp] router-id 1.1.1.1
[SwitchA-bgp] peer 200.1.2.2 as-number 20
[SwitchA-bgp] network 9.1.1.0 255.255.255.0
[SwitchA-bgp] quit
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 20
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 200.1.2.1 as-number 10
[SwitchB-bgp] peer 200.1.3.2 as-number 30
[SwitchB-bgp] quit
# Configure Switch C.
<SwitchC> system-view
[SwitchC] bgp 30
[SwitchC-bgp] router-id 3.3.3.3
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