Chapter 38 Configuring IP Unicast Routing

Configuring Multi-VRF CE

Configuring BGP PE to CE Routing Sessions

Beginning in privileged EXEC mode, follow these steps to configure a BGP PE to CE routing session:

 

Command

Purpose

Step 1

 

 

configure terminal

Enter global configuration mode.

Step 2

 

 

router bgp autonomous-system-number

Configure the BGP routing process with the AS number

 

 

passed to other BGP routers, and enter router

 

 

configuration mode.

Step 3

 

 

network network-number mask

Specify a network and mask to announce using BGP.

 

network-mask

 

Step 4

 

 

redistribute ospf process-idmatch

Set the switch to redistribute OSPF internal routes.

 

internal

 

Step 5

 

 

network network-number area area-id

Define a network address and mask on which OSPF runs

 

 

and the area ID for that network address.

Step 6

 

 

address-family ipv4 vrf vrf-name

Define BGP parameters for PE to CE routing sessions, and

 

 

enter VRF address-family mode.

Step 7

 

 

neighbor address remote-as as-number

Define a BGP session between PE and CE routers.

Step 8

 

 

neighbor address activate

Activate the advertisement of the IPv4 address family.

Step 9

 

 

end

Return to privileged EXEC mode.

Step 10

 

 

show ip bgp [ipv4] [neighbors]

Verify BGP configuration.

Step 11

 

 

copy running-config startup-config

(Optional) Save your entries in the configuration file.

 

 

 

Use the no router bgp autonomous-system-numberglobal configuration command to delete the BGP routing process. Use the command with keywords to delete routing characteristics.

Multi-VRF CE Configuration Example

Figure 38-7is a simplified example of the physical connections in a network similar to that in

Figure 38-6. OSPF is the protocol used in VPN1, VPN2, and the global network. BGP is used in the CE to PE connections. The examples following the illustration show how to configure a Catalyst 3750-E or 3560-E switch as CE Switch A, and the VRF configuration for customer switches D and F. Commands for configuring CE Switch C and the other customer switches are not included but would be similar. The example also includes commands for configuring traffic to Switch A for a Catalyst 6000 or Catalyst 6500 switch acting as a PE router.

 

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

38-70

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Cisco Systems 3750E manual Configuring BGP PE to CE Routing Sessions, Multi-VRF CE Configuration Example, 38-70