Ipv4 Bgp Configuration Examples; Basic Bgp Configuration Example - HP 6125XLG Configuration Manual

IPv4 BGP configuration examples

Basic BGP configuration example

Network requirements
In Figure 57, run EBGP between Switch A and Switch B, and run IBGP between Switch B and Switch C
so that Switch C can access the network 8.1.1.0/24 connected to Switch A.
Figure 57 Network diagram
Configuration considerations
To prevent route flapping caused by port state changes, this example uses loopback interfaces to
establish IBGP connections. Because loopback interfaces are virtual interfaces, use the peer
connect-interface command to specify the loopback interface as the source interface for establishing
BGP connections. Enable OSPF in AS 65009 to make sure that Switch B can communicate with Switch
C through loopback interfaces.
The EBGP peers, Switch A and Switch B (usually belong to different carriers), are located in different ASs.
Typically, their loopback interfaces are not reachable to each other, so directly connected interfaces are
used for establishing BGP sessions. To enable Switch C to access the network 8.1.1.0/24 connected
directly to Switch A, inject network 8.1.1.0/24 to the BGP routing table of Switch A.
Configuration procedure
Configure IP addresses for interfaces. (Details not shown.)
1.
2. Configure IBGP:
# Configure Switch B.
<SwitchB> system-view
[SwitchB] bgp 65009
[SwitchB-bgp] router-id 2.2.2.2
[SwitchB-bgp] peer 3.3.3.3 as-number 65009
[SwitchB-bgp] peer 3.3.3.3 connect-interface loopback 0
[SwitchB-bgp] ipv4-family unicast
[SwitchB-bgp-ipv4] peer 3.3.3.3 enable
[SwitchB-bgp-ipv4] quit
[SwitchB-bgp] quit
[SwitchB] ospf 1
[SwitchB-ospf-1] area 0
[SwitchB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0
[SwitchB-ospf-1-area-0.0.0.0] network 9.1.1.1 0.0.0.255
[SwitchB-ospf-1-area-0.0.0.0] quit
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