Published On: August 6ᵗʰ, 2019 02:13

IP Routing: BGP Configuration Guide, Cisco IOS XE Release 3S

BGP NSR provides BGP nonstop routing (NSR) and nonstop forwarding (NSF) in the event of a switchover from an Active RP to the Standby RP. The BGP NSR Support for iBGP Peers feature provides NSR support for iBGP peers configured under the IPv4 unicast or IPv4 + label address family.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

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.

Restrictions on BGP NSR Support for iBGP Peers

This feature applies to iBGP peers configured under IPv4 unicast or IPv4 + label address families.

Information About BGP NSR Support for iBGP Peers

Benefit of BGP NSR Support for iBGP Peers

Nonstop routing is beneficial for iBGP peers because it reduces the likelihood of dropped packets during switchover from the Active RP to the Standby RP. Switchover occurs when the Active RP fails for some reason, and the Standby RP takes control of Active RP operations.

How to Configure BGP NSR Support for iBGP Peers

Making an iBGP Peer NSR-Capable for the IPv4 Address Family

SUMMARY STEPS

1. enable

2. configure terminal

3. router bgp autonomous-system-number

4. address-family ipv4 [unicast | vrf vrf-name]

5. neighbor ip-address remote-as as-number

6. neighbor ip-address activate

7. neighbor ip-address ha-mode sso

8. 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 4000
 

Enters router configuration mode for the specified routing process.

 
Step 4 address-family ipv4 [unicast | vrf vrf-name]

Example:
Device(config-router)# address-family ipv4 unicast
 

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

  • The unicast keyword specifies the IPv4 unicast address family.

  • The vrf keyword and vrf-name argument specify the name of the virtual routing and forwarding (VRF) instance to associate with subsequent IPv4 address family configuration mode commands.

 
Step 5 neighbor ip-address remote-as as-number


Example:
Device(config-router-af)# neighbor 192.168.1.1 remote-as 4000
 

Specifies the autonomous system of the neighbor.

 
Step 6 neighbor ip-address activate


Example:
Device(config-router-af)# neighbor 192.168.1.1 activate
 

Activates the specified peer.

 
Step 7 neighbor ip-address ha-mode sso


Example:
Device(config-router-af)# neighbor 192.168.1.1 ha-mode sso
 

Configures a BGP neighbor to support BGP NSR with stateful switchover (SSO).

 
Step 8 end


Example:
Device(config-router-af)# end
 

Exits address family configuration mode and returns to privileged EXEC mode.

 

Making an iBGP Peer NSR-Capable for the VPNv4 Address Family

SUMMARY STEPS

1. enable

2. configure terminal

3. router bgp autonomous-system-number

4. neighbor ip-address remote-as as-number

5. neighbor ip-address ha-mode sso

6. address-family vpnv4 [unicast]

7. neighbor ip-address activate

8. 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 4000
 

Enters router configuration mode for the specified routing process.

 
Step 4 neighbor ip-address remote-as as-number


Example:
Device(config-router)# neighbor 192.168.1.1 remote-as 4000
 

Specifies the autonomous system of the neighbor.

 
Step 5 neighbor ip-address ha-mode sso


Example:
Device(config-router)# neighbor 192.168.1.1 ha-mode sso
 

Configures a BGP neighbor to support BGP NSR with stateful switchover (SSO).

 
Step 6 address-family vpnv4 [unicast]

Example:
Device(config-router)# address-family VPNv4 unicast
 

Specifies the VPNv4 address family and enters address family configuration mode.

 
Step 7 neighbor ip-address activate


Example:
Device(config-router-af)# neighbor 192.168.1.1 activate
 

Activates the specified peer.

 
Step 8 end


Example:
Device(config-router-af)# end
 

Exits address family configuration mode and returns to privileged EXEC mode.

 

Making an iBGP Peer NSR Capable at the Router Level

SUMMARY STEPS

1. enable

2. configure terminal

3. router bgp autonomous-system-number

4. neighbor ip-address remote-as as-number

5. neighbor ip-address activate

6. neighbor ip-address ha-mode sso

7. end

8. show ip bgp sso summary


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 4000
 

Enters router configuration mode for the specified routing process.

 
Step 4 neighbor ip-address remote-as as-number


Example:
Device(config-router)# neighbor 192.168.1.1 remote-as 4000
 

Specifies the autonomous system of the neighbor.

 
Step 5 neighbor ip-address activate


Example:
Device(config-router)# neighbor 192.168.1.1 activate
 

Activates the specified neighbor.

 
Step 6 neighbor ip-address ha-mode sso


Example:
Device(config-router)# neighbor 192.168.1.1 ha-mode sso
 

Configures the specified peer to be NSR capable in all of the NSR-supported address families under which that peer has been activated.

 
Step 7 end


Example:
Device(config-router)# end
 

Exits configuration mode and returns to privileged EXEC mode.

 
Step 8 show ip bgp sso summary


Example:
Device# show ip bgp sso summary
 

(Optional) Displays information about stateful switchover (sso) and whether a peer has NSR enabled or disabled.

 

Configuration Examples for BGP NSR Support for an iBGP Peer

Example: Configuring an iBGP Peer To Be NSR Capable

Configuring an iBGP Peer to Be NSR Capable at the Address Family Level

router bgp 4000
 address-family ipv4 unicast
 neighbor 192.168.1.1 remote-as 4000
 neighbor 192.168.1.1 activate
 neighbor 192.168.1.1 ha-mode sso

Configuring an iBGP Peer to Be NSR Capable at the Router Level

router bgp 4000
 neighbor 192.168.1.1 remote-as 4000
 neighbor 192.168.1.1 activate 
 neighbor 192.168.1.1 ha-mode sso

Additional References

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

BFD commands

Cisco IOS IP Routing: Protocol Independent Command Reference

Configuring BFD support for another routing protocol

IP Routing: BFD Configuration Guide

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http:/​/​www.cisco.com/​cisco/​web/​support/​index.html

Feature Information for BGP NSR Support for iBGP Peers

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 NSR Support for iBGP Peers

Feature Name

Releases

Feature Information

BGP NSR Support for iBGP Peers

Cisco IOS XE Release 3.6S

Cisco IOS XE Release 3.7S

BGP NSR provides BGP nonstop routing and nonstop forwarding in the event of a switchover from an active RP to the standby RP.

The following commands were modified: neighbor ha-mode sso and show ip bgp vpnv4 all sso summary.