- Read Me First
- Cisco BGP Overview
- BGP 4
- Configuring a Basic BGP Network
- BGP 4 Soft Configuration
- BGP Support for 4-byte ASN
- IPv6 Routing: Multiprotocol BGP Extensions for IPv6
- IPv6 Routing: Multiprotocol BGP Link-Local Address Peering
- IPv6 Multicast Address Family Support for Multiprotocol BGP
- Configuring Multiprotocol BGP (MP-BGP) Support for CLNS
- BGP IPv6 Admin Distance
- Connecting to a Service Provider Using External BGP
- BGP Route-Map Continue
- BGP Route-Map Continue Support for Outbound Policy
- Removing Private AS Numbers from the AS Path in BGP
- Configuring BGP Neighbor Session Options
- BGP Neighbor Policy
- BGP Dynamic Neighbors
- BGP Support for Next-Hop Address Tracking
- BGP Restart Neighbor Session After Max-Prefix Limit Reached
- BGP Support for Dual AS Configuration for Network AS Migrations
- Configuring Internal BGP Features
- BGP VPLS Auto Discovery Support on Route Reflector
- BGP FlowSpec Route-reflector Support
- BGP Flow Specification Client
- BGP NSF Awareness
- BGP Graceful Restart per Neighbor
- BGP Support for BFD
- IPv6 NSF and Graceful Restart for MP-BGP IPv6 Address Family
- BGP Link Bandwidth
- Border Gateway Protocol Link-State
- iBGP Multipath Load Sharing
- BGP Multipath Load Sharing for Both eBGP and iBGP in an MPLS-VPN
- Loadsharing IP Packets over More Than Six Parallel Paths
- BGP Policy Accounting
- BGP Policy Accounting Output Interface Accounting
- BGP Cost Community
- BGP Support for IP Prefix Import from Global Table into a VRF Table
- BGP Support for IP Prefix Export from a VRF Table into the Global Table
- BGP per Neighbor SoO Configuration
- Per-VRF Assignment of BGP Router ID
- BGP Next Hop Unchanged
- BGP Support for the L2VPN Address Family
- BGP Event-Based VPN Import
- BGP Best External
- BGP PIC Edge for IP and MPLS-VPN
- Detecting and Mitigating a BGP Slow Peer
- Configuring BGP: RT Constrained Route Distribution
- Configuring a BGP Route Server
- BGP Diverse Path Using a Diverse-Path Route Reflector
- BGP Enhanced Route Refresh
- Configuring BGP Consistency Checker
- BGP—Origin AS Validation
- BGP MIB Support
- BGP 4 MIB Support for Per-Peer Received Routes
- BGP Support for Nonstop Routing (NSR) with Stateful Switchover (SSO) Using L2VPN VPLS
- BGP NSR Auto Sense
- BGP NSR Support for iBGP Peers
- BGP Graceful Shutdown
- BGP — mVPN BGP sAFI 129 - IPv4
- BGP-MVPN SAFI 129 IPv6
- BFD—BGP Multihop Client Support, cBit (IPv4 and IPv6), and Strict Mode
- BGP Attribute Filter and Enhanced Attribute Error Handling
- BGP Additional Paths
- BGP-Multiple Cluster IDs
- BGP-VPN Distinguisher Attribute
- BGP-RT and VPN Distinguisher Attribute Rewrite Wildcard
- VPLS BGP Signaling
- Multicast VPN BGP Dampening
- BGP—IPv6 NSR
- BGP-VRF-Aware Conditional Advertisement
- BGP—Selective Route Download
- BGP—Support for iBGP Local-AS
- eiBGP Multipath for Non-VRF Interfaces (IPv4/IPv6)
- L3VPN iBGP PE-CE
- BGP NSR Support for MPLS VPNv4 and VPNv6 Inter-AS Option B
- BGP-RTC for Legacy PE
- BGP PBB EVPN Route Reflector Support
- BGP Monitoring Protocol
- VRF Aware BGP Translate-Update
- BGP Support for MTR
- BGP Accumulated IGP
- BGP MVPN Source-AS Extended Community Filtering
- BGP AS-Override Split-Horizon
- BGP Support for Multiple Sourced Paths Per Redistributed Route
- Maintenance Function: BGP Routing Protocol
- Finding Feature Information
- Prerequisites for VRF Aware BGP Translate-Update
- Restrictions for VRF Aware BGP Translate-Update
- Information About VRF Aware BGP Translate-Update
- How To Configure VRF Aware BGP Translate-Update
- Configuration Examples for VRF Aware BGP Translate-Update
- Additional References for VRF Aware BGP Translate-Update
- Feature Information for VRF Aware BGP Translate-Update
VRF Aware BGP Translate-Update
The VRF aware BGP translate-update feature enables multicast forwarding on those customer-edge (CE) devices, which have an older version of Cisco software that does not support multicast BGP (mBGP) routing.
The provider-edge (PE) devices establish a virtual routing and forwarding (VRF) session with the neighbor CE devices, and configure the translate-update feature under an IPv4/IPv6 VRF address family. The PE devices translate the updates from unicast to multicast on CE devices and put them as multicast updates in the Border Gateway Protocol (BGP) VRF routing table of the PE devices for processing.
- Finding Feature Information
- Prerequisites for VRF Aware BGP Translate-Update
- Restrictions for VRF Aware BGP Translate-Update
- Information About VRF Aware BGP Translate-Update
- How To Configure VRF Aware BGP Translate-Update
- Configuration Examples for VRF Aware BGP Translate-Update
- Additional References for VRF Aware BGP Translate-Update
- Feature Information for VRF Aware BGP Translate-Update
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.
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.
Prerequisites for VRF Aware BGP Translate-Update
-
The VRF aware translate-update feature applies only to IPv4/IPv6 virtual routing and forwarding (VRF) address-families.
-
You must use peer-group for the configuration of the neighbor under IPv4/IPv6 VRF address families.
-
BGP neighbors that are only capable of unicast routing, must be activated under both unicast and multicast address families.
-
BGP neighbors must also be enabled under the compatible multicast address family for the VRF aware translate-update feature to function as designed.
-
The provider-edge (PE) devices must have multicast VRF enabled and must have a session established with the customer-edge (CE) devices.
Restrictions for VRF Aware BGP Translate-Update
-
You must not configure (nonVRF) IPv4/IPv6 address families for the VRF aware BGP translate-update feature. The IPv4/IPv6 address family must be configured for multicast routing using the Subsequent Address Family Identifier (SAFI) feature.
-
The VRF aware BGP translate-update feature does not support configuration of BGP neighbor using peer-template.
Information About VRF Aware BGP Translate-Update
VRF Aware BGP Translate-Update Overview
The VRF aware BGP translate-update feature enables multicast forwarding on those customer-edge (CE) devices, which have an older version of Cisco software that does not support multicast BGP (mBGP) routing.
This feature is analogous to the Subsequent Address Family Identifier (SAFI), which provides the capability to support multicast routing in the service provider's core IPv4 network, but is limited in support to IPv4/IPv6 address families. In the case of the virtual routing and forwarding (VRF) aware BGP translate-update feature, provider-edge (PE) devices establish a VRF session with the neighbor CE devices, and have the translate-update feature configured under an IPv4/IPv6 VRF address family.
When the neighbor translate-update command is configured on a PE device under the (IPv4 VRF) address-family configuration mode or the (IPv6 VRF) address-family configuration mode, the PE devices translate the updates from unicast to multicast on CE devices and put them in the Border Gateway Protocol (BGP) VRF routing table of the PE devices, as multicast updates, for processing. If you also configure the optional keyword unicast, the updates that are not translated, are placed in the PE device's unicast queue and populates the unicast VRF BGP table. The translation from unicast to multicast routes occurs from CE devices to PE devices only, and the multicast and unicast prefixes are only advertised from the CE device to the PE device's multicast neighbors.
For example, when you configure the VRF aware BGP translate-update feature under a VRF (v1) for a neighbor CE device (CE1), a neighbor topology under the IPv4-multicast-VRF or IPv6-multicast-VRF address-family is added to CE1's session with a PE device (PE1). The multicast-VRF neighbor topology does not actively participate in these multicast sessions and only forwards announcements that arrive from CE1. Once such announcements arrive, they are translated into multicast and placed in the nonactive multicast VRF neighbor's routing table. The Cisco software ensures that the routes advertised by CE1 configured under the IPv4/IPv6 VRF address-family are available on PE1's IPv4/IPv6 multicast VRF v1 address-family BGP table. These routes, along with PE1's IPv4/IPv6 multicast VRF v1 address-family BGP table, are advertised to PE1's multicast peers if you have configured the neighbor translate-update command . The routes are also advertised to PE1's unicast peers if you have also configured the optional keyword unicast.
The unicast keyword is optional, yet significant, as it enables the PE devices to place unicast advertisements from the CE devices in the unicast BGP table of the PE devices. Therefore, route advertisements from CE devices populates both unicast and multicast BGP tables, else CE device's routes only populate the PE device's multicast BGP table.
Note | You must also enable address-family under the compatible multicast address-family for VRF aware BGP translate-update feature to function as designed. |
How To Configure VRF Aware BGP Translate-Update
Configuring VRF Aware BGP Translate-Update
Perform this task to configure VRF aware BGP translate-update feature:
1.
enable
2.
configure
terminal
3.
router
bgp
as-number
4.
address-family
ipv4 [mdt
|
tunnel
| {multicast
|
unicast} [vrf
vrf-name]
|
vrf
vrf-name]
5.
neighbor
peer-group-name
peer-group
6.
neighbor {ipv4-addr
|
ipv6-addr
|
peer-group-name}
remote-as
autonomous-system-number
7.
neighbor {ipv4-addr
|
ipv6-addr}
peer-group
peer-group-name
8.
neighbor {ipv4-addr
|
ipv6-addr
|
peer-group-name}
activate
9.
neighbor {ipv4-address |
ipv6-address}
translate-update
multicast [unicast]
10.
end
11.
show
bgp
vpnv4
multicast {all
|
vrf
vrf-name
|
rd
route-distinguisher}
12.
show
ip
route
multicast
vrf
vrf-name
13.
show
running-config
DETAILED STEPS
Removing the VRF Aware BGP Translate-Update Configuration
Perform this task to disable the VRF aware BGP translate-update feature:
1.
enable
2.
configure
terminal
3.
router
bgp
as-number
4.
address-family
ipv4 [mdt
|
tunnel
| {multicast
|
unicast} [vrf
vrf-name]
|
vrf
vrf-name]
5.
no
neighbor {ipv4-address |
ipv6-address}
translate-update
multicast [unicast]
6.
end
7.
show
running-config
DETAILED STEPS
Configuration Examples for VRF Aware BGP Translate-Update
- Example: Configuring VRF aware BGP Translate-Update
- Example: Removing VRF aware BGP Translate-Update Configuration
Example: Configuring VRF aware BGP Translate-Update
The following example shows how to configure the translate-update feature for an IPv4 VRF address-family named v1 and BGP neighbor n2 peer-group for VRF configuration:
Note | Peer-template configuration for BGP neighbor is not supported for this feature due to conflicts with the earlier versions of Cisco software. |
Device> enable Device# configure terminal Device(config)# router bgp 65000 Device(config-router)# address-family ipv4 vrf v1 Device(config-router-af)# neighbor n2 peer-group Device(config-router-af)# neighbor n2 remote-as 4 Device(config-router-af)# neighbor 10.1.1.1 peer-group n2 Device(config-router-af)# neighbor 10.1.1.1 activate Device(config-router-af)# neighbor 10.1.1.1 translate-update multicast unicast Device(config-router-af)# end
The following is sample output from the show bgp vpnv4 multicast vrf command. As the VRF aware BGP translate-update feature is configured, the state of the neighbor displays “NoNeg”:
Device# show bgp vpnv4 multicast vrf v1 summary BGP router identifier 10.1.3.1, local AS number 65000 BGP table version is 8, main routing table version 8 7 network entries using 1792 bytes of memory 8 path entries using 960 bytes of memory 5/3 BGP path/bestpath attribute entries using 1280 bytes of memory 3 BGP AS-PATH entries using 88 bytes of memory 2 BGP extended community entries using 48 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 4168 total bytes of memory BGP activity 23/2 prefixes, 33/9 paths, scan interval 60 secs Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 10.1.1.1 4 4 5 10 1 0 0 00:01:10 (NoNeg) 10.1.3.2 4 2 12 10 8 0 0 00:01:33
The following is sample output from the show ip route multicast vrf command:
Note | The routes configured using the translate-update feature does not have the “+” symbol against the prefixes in the Routing Information Base (RIB) table. Appearance of the symbol in the first entry indicates that the unicast route has leaked into the multicast table. However, the second entry is a translate-update route, which appears to be a multicast route. |
Device# show ip route multicast vrf v1 B + 10.1.1.0/24 [20/0] via 10.1.1.1 (v1), 00:00:08 B 10.1.1.0/24 [20/0] via 10.1.1.1 (v1), 00:00:42
The following is sample output from the show running-config command:
Note | The provider-edge (PE) device must activate its BGP neighbor under the multicast address-family even though the neighbor is not capable of multicast routing. If the unicast address-family identifier has the route-map configured and multicast address-family identifier has no route-map configured, the unicast route-map controls the route under the unicast table but not the route under multicast table. |
Device# show running-config address-family ipv4 vrf v1 redistribute connected redistribute static neighbor 10.1.1.1 remote-as 4 neighbor 10.1.1.1 activate neighbor 10.1.1.1 translate-update multicast unicast neighbor 10.1.1.1 remote-as 4 neighbor 10.1.1.1 activate exit-address-family ! address-family ipv4 multicast vrf v1 redistribute connected redistribute static neighbor 10.1.1.1 remote-as 4 neighbor 10.1.1.1 activate neighbor 10.1.1.1 soft-reconfiguration inbound neighbor 10.1.1.1 route-map x in exit-address-family
Note | The “neighbor 10.1.1.1 soft-reconfiguration inbound” and the “ neighbor 10.1.1.1 route-map x in” field in the output indicate that only the routes in the BGP multicast table are affected. |
The following is sample output from the show running-config command when you configure a neighbor under different address-families:
Note | Configuring the BGP neighbor under different address-families manipulates the unicast routes and multicast routes advertised to the neighbor. |
Configuration for IPv4/IPv6 unicast address-family:
Device# show running-config address-family ipv4 neighbor 20.2.2.1 activate neighbor 20.2.2.1 translate-update multicast unicast exit-address-family ! address-family ipv4 multicast neighbor 20.2.2.1 activate exit-address-family !
Configuration for IPv4/IPv6 VRF unicast address-family:
Device# show running-config address-family ipv4 vrf v1 neighbor 20.2.2.1 remote-as 4 neighbor 20.2.2.1 activate neighbor 20.2.2.1 translate-update multicast unicast exit-address-family ! address-family ipv4 multicast vrf v1 neighbor 20.2.2.1 remote-as 4 neighbor 20.2.2.1 activate exit-address-family !
The following is sample configuration of the translate-update feature from a device with the old version of Cisco Software. The neighbor, in this case, is configured for IPv4/IPv6 unicast address-family, without running the address-family command:
Configuration in the old format, without an address-family configured:
Device> enable Device# configure terminal Device(config)# router bgp 65000 Device(config-router)# neighbor 20.2.2.1 remote-as 4 Device(config-router)# neighbor 20.2.2.1 translate-update nlri ipv4 multicast unicast Device(config-router-af)# end
Configuration in the new format, without an address-family configured:
Device> enable Device# configure terminal Device(config)# router bgp 65000 Device(config-router)# neighbor 20.2.2.1 remote-as 4 Device(config-router)# neighbor 20.2.2.1 translate-update nlri multicast unicast Device(config-router-af)# end
Example: Removing VRF aware BGP Translate-Update Configuration
The following example shows how to disable the VRF aware BGP translate-update feature for an IPv4 VRF address-family named v1 and BGP neighbor n2 peer-group for VRF:
Note | Disabling the translate-update configuration for a neighbor deletes the pseudo multicast neighbor and flaps the session, similar to removing the neighbor from a multicast session: |
Device> enable Device# configure terminal Device(config)# router bgp 65000 Device(config-router)# address-family ipv4 vrf v1 Device(config-router-af)# no neighbor 10.1.1.1 translate-update multicast unicast Device(config-router-af)# end
The following output displays the debug logs after you disable the translate-update feature on the neighbor:
*Nov 20 07:09:15.902: %BGP_SESSION-5-ADJCHANGE: neighbor 2.2.2.1 IPv4 Multicast vpn vrf v1 topology base removed from session Neighbor deleted *Nov 20 07:09:15.902: %BGP-5-ADJCHANGE: neighbor 2.2.2.1 vpn vrf v1 Down Neighbor deleted *Nov 20 07:09:15.902: %BGP_SESSION-5-ADJCHANGE: neighbor 2.2.2.1 IPv4 Unicast vpn vrf v1 topology base removed from session Neighbor deleted *Nov 20 07:09:16.877: %BGP-5-ADJCHANGE: neighbor 2.2.2.1 vpn vrf v1 Up
The following is sample output from the show running-config command:
Note | The associated neighbor 10.1.1.1 is removed even from the nonvolatile generation (NVGEN) after translate-update is disabled on that neighbor. |
Device# show running-config address-family ipv4 vrf v1 redistribute connected redistribute static neighbor 10.1.1.1 remote-as 4 neighbor 10.1.1.1 activate exit-address-family ! address-family ipv4 multicast vrf v1 redistribute connected redistribute static exit-address-family
Additional References for VRF Aware BGP Translate-Update
Related Documents
Related Topic | Document Title |
---|---|
Cisco IOS commands |
|
BGP commands |
Technical Assistance
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Feature Information for VRF Aware BGP Translate-Update
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.
Feature Name |
Releases |
Feature Information |
---|---|---|
VRF aware BGP Translate-Update |
The VRF aware BGP translate-update feature enables multicast forwarding on those customer-edge (CE) devices, which have an older version of Cisco software that does not support multicast BGP (mBGP) routing. The following command was introduced: neighbor translate-update |