3Com Switch 8800 Advanced Software V5 Configuration Guide

456 CHAPTER 35: BGP CONFIGURATION
4 Configure MED
# Configure the default MED of SwitchB.
[SwitchB] bgp 65009
[SwitchB-bgp] default med 100
# Display the routing table on SwitchA.
[SwitchA] display bgp routing-table
Total Number of Routes: 3
BGP Local router ID is 1.1.1.1
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
*> 8.0.0.0 0.0.0.0 0 0 i
*> 9.1.1.0/24 200.1.2.1 0 0 65009i
* 200.1.1.1 100 0 65009i
From the above information, you can find the route with the next hop 200.1.2.1 is
the best route, because its MED (0) is smaller than the MED (100) of the other
route with the next hop 200.1.1.1 (Switch B).
BGP Community
Configuration
Network requirements
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.
Network diagram
Figure 149 Network diagram for BGP community configuration (on switches)
Configuration procedure
1 Configure IP addresses for interfaces (omitted)
2 Configure EBGP
# Configure SwitchA
Switch A
Switch B Switch C
AS 20
AS 30
AS 10
Vlan-int200
200.1.2.2/24
Vlan-int300
200.1.3.1/24
Vlan-int300
200.1.3.2/24
Vlan-int200
200.1.2.1/24
EBGP
EBGP
Vlan-int100
9.1.1 .1/24