Bgp Path Selection Configuration Example - HP 6125XLG Configuration Manual

BGP routing table information of 9.1.1.0/24:
From
Relay nexthop
Original nexthop: 10.1.3.1
OutLabel
AS-path
Origin
Attribute value : MED 0, localpref 100, pref-val 0, pre 255
State
The output indicates the following:
Switch F can send route information to Switch B and Switch C through the confederation by
•
establishing only an EBGP connection with Switch A.
Switch B and Switch D are in the same confederation, but belong to different sub-ASs. They obtain
•
external route information from Switch A and generate the same BGP route entries as if they were
in one AS, although they have no direct connection in between.

BGP path selection configuration example

Network requirements
In Figure 64, all switches run BGP. EBGP runs between Switch A and Switch B, and between Switch A
and Switch C. IBGP runs between Switch B and Switch D, and between Switch D and Switch C. OSPF is
the IGP protocol in AS 200.
Configure routing policies, making Switch D use the route 1.0.0.0/8 from Switch C as the optimal.
Figure 64 Network diagram
Device
Switch A
Switch B
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown.)
2. Configure OSPF on Switch B, Switch C, and Switch D:
: 10.1.3.1 (1.1.1.1)
: 10.1.3.1
: NULL
: 100
: igp
: valid, internal-confed, best,
Interface IP address
Vlan-int101 1.0.0.1/8
Vlan-int100 192.1.1.1/24
Vlan-int200 193.1.1.1/24
Vlan-int100 192.1.1.2/24
Vlan-int300 194.1.1.2/24
Device
Switch D
Switch C
248
Interface IP address
Vlan-int400 195.1.1.1/24
Vlan-int300 194.1.1.1/24
Vlan-int400 195.1.1.2/24
Vlan-int200 193.1.1.2/24