BGP MVPN Source-AS Extended Community Filtering

The BGP MVPN Source-AS Extended Community Filtering feature enables the provider edge (PE) device to suppress attaching the multicast VPN (MVPN)-related extended communities to routes learned from a customer edge (CE) device or redistributed in a virtual routing and forwarding (VRF) instance for a specified neighbor.

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Information About BGP MVPN Source-AS Extended Community Filtering

Overview of BGP MVPN Source-AS Extended Community Filtering

VPN routes carry special extended communities (source autonomous system [AS] extended community and virtual routing and forwarding [VRF] route import extended community) to support multicast VPN (MVPN). Legacy provider edge (PE) devices interpret the source AS extended community as old style multicast distribution tree (MDT). You can attach the extended communities when the prefix is created. After the BGP MVPN Source-AS Extended Community Filtering feature is enabled, this allows the PE device to suppress these extended communities. You can use this functionality to suppress extended communities from being sent for Subsequent Address Family Identifier (SAFI) 128 routes and instead use SAFI 129. Devices with SAFI 129 must be able to identify the source AS extended community correctly.

How to Configure BGP MVPN Source-AS Extended Community Filtering

Configuring BGP MVPN Source-AS Extended Community Filtering

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router bgp autonomous-system-number
  4. address-family ipv4 vrf vrf-name
  5. unicast-reachability [source-as | vrf-route-import ] [disable ]
  6. end

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

router bgp autonomous-system-number

Example:


Device(config)# router bgp 45000

Enters router configuration mode for the specified routing process.

Step 4

address-family ipv4 vrf vrf-name

Example:


Device(config-router)# address-family ipv4 vrf vpn1

Specifies the IPv4 address family and enters address family configuration mode.

  • Use the vrf keyword and vrf-name argument to specify the name of the VRF instance to associate with subsequent IPv4 address family configuration mode commands.

Step 5

unicast-reachability [source-as | vrf-route-import ] [disable ]

Example:


Device(config-router-af)# unicast-reachability source-as disable

Disables advertising extended communities for non-MVPN profiles.

Step 6

end

Example:


Device(config-router-af)# end

Exits address family configuration mode and enters privileged EXEC mode.

Configuration Examples for BGP MVPN Source-AS Extended Community Filtering

Example: Configuring BGP MVPN Source-AS Extended Community Filtering

The following example configures BGP MVPN source-AS extended community filtering: 

Device# configure terminal
Device(config)# router bgp 45000
Device(config)# address-family ipv4 vrf vpn1
Device(config-router-af)# unicast-reachability source-as disable
Device(config-router-af)# exit

The following example shows summary output for the show ip bgp vpnv4 vrf vpn1 command. 

Device# show ip bgp vpnv4 vrf vpn1

BGP routing table entry for 10:10:1.1.1.1/32, version 25
Paths: (2 available, best #2, table red)
Multipath: eiBGP
  Advertised to update-groups:
     1         
  Refresh Epoch 1
  Local, imported path from 10:11:1.1.1.1/32 (global)
    1.1.1.2 (metric 11) (via default) from 1.1.1.5 (1.1.1.5)
      Origin incomplete, metric 11, localpref 100, valid, internal
      Extended Community: RT:1:1 OSPF DOMAIN ID:0x0005:0x000000C80200 
        MVPN AS:55:0.0.0.0 MVPN VRF:1.1.1.2:2 OSPF RT:0.0.0.0:2:0 
        OSPF ROUTER ID:10.10.20.2:0
      Originator: 1.1.1.2, Cluster list: 1.1.1.5
      Connector Attribute: count=1
       type 1 len 12 value 10:11:1.1.1.2
      mpls labels in/out 20/21
      rx pathid: 0, tx pathid: 0
  Refresh Epoch 1
  Local
    10.10.10.100 (via vrf red) from 0.0.0.0 (1.1.1.1)
      Origin incomplete, metric 11, localpref 100, weight 32768, valid, sourced, best
      Extended Community: RT:1:1 OSPF DOMAIN ID:0x0005:0x000000C80200 
        MVPN VRF:1.1.1.1:1 OSPF RT:0.0.0.0:2:0 OSPF ROUTER ID:10.10.10.1:0
      mpls labels in/out 20/nolabel
      rx pathid: 0, tx pathid: 0x0

Additional References for BGP MVPN Source-AS Extended Community Filtering

Related Documents

Related Topic Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

BGP commands

Cisco IOS IP Routing: BGP Command Reference

BGP concepts and tasks

IP Routing: BGP Configuration Guide

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Feature Information for BGP MVPN Source-AS Extended Community Filtering

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1. Feature Information for BGP MVPN Source-AS Extended Community Filtering

Feature Name

Releases

Feature Information

BGP MVPN Source-AS Extended Community Filtering

Cisco IOS XE Release 3.13S

The BGP MVPN Source-AS Extended Community Filtering feature enables the provider edge (PE) device to suppress attaching the multicast VPN (MVPN)-related extended communities to routes learned from a customer edge (CE) device or redistributed in a virtual routing and forwarding (VRF) instance for a specified neighbor.

The following command was introduced or modified: unicast-reachability .