- Any Transport over MPLS
- MPLS MTU Command Changes
- AToM Static Pseudowire Provisioning
- L2VPN Interworking
- L2VPN Pseudowire Switching
- L2VPN Pseudowire Redundancy
- VPLS Autodiscovery BGP Based
- H VPLS N PE Redundancy for QinQ and MPLS Access
- L2VPN Multisegment Pseudowires
- QoS Policy Support for L2VPN ATM PVPs
- L2VPN Pseudowire Preferential Forwarding
- MPLS Pseudowire Status Signaling
- Feature Information For
- Prerequisites for VPLS Autodiscovery BGP Based
- Restrictions for VPLS Autodiscovery BGP Based
- Information About VPLS Autodiscovery BGP Based
- How to Configure VPLS Autodiscovery BGP Based
- Configuration Examples for VPLS Autodiscovery BGP Based
- Additional References
- Feature Information for VPLS Autodiscovery BGP Based
VPLS Autodiscovery BGP Based
VPLS Autodiscovery enables each Virtual Private LAN Service (VPLS) provider edge (PE) router to discover which other PE routers are part of the same VPLS domain. VPLS Autodiscovery also automatically detects when PE routers are added to or removed from the VPLS domain. You no longer need to manually configure the VPLS and maintain the configuration when a PE router is added or deleted. VPLS Autodiscovery uses the Border Gateway Protocol (BGP) to discover the VPLS members and to set up and tear down pseudowires in the VPLS.
- Feature Information For
- Prerequisites for VPLS Autodiscovery BGP Based
- Restrictions for VPLS Autodiscovery BGP Based
- Information About VPLS Autodiscovery BGP Based
- How to Configure VPLS Autodiscovery BGP Based
- Configuration Examples for VPLS Autodiscovery BGP Based
- Additional References
- Feature Information for VPLS Autodiscovery BGP Based
Feature Information For
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.
Prerequisites for VPLS Autodiscovery BGP Based
Before configuring VPLS Autodiscovery, if you are using a Cisco 7600 series router, perform the Cisco 7600 router-specific tasks listed in the section called "Virtual Private LAN Services on the Optical Service Modules" in the Cisco 7600 Series Router IOS Software Configuration Guide.
Restrictions for VPLS Autodiscovery BGP Based
- VPLS Autodiscovery supports only IPV4 addresses.
- VPLS Autodiscovery uses Forwarding Equivalence Class (FEC) 129 to convey endpoint information. Manually configured pseudowires use FEC 128.
- VPLS Autodiscovery is not supported with Layer 2 Tunnel Protocol Version 3 (L2TPv3).
- VPLS Autodisocovery is not supported with interautonomous system configurations.
- You can configure both autodiscovered and manually configured pseudowires in a single virtual forwarding instance (VFI). However, the pseudowires cannot go to the same peer PE router.
- If you manually configure a neighbor using the neighbor (VPLS)command after you have enabled VPLS Autodiscovery and both peers are in autodiscovery mode, manually configure the route target (RT) values to prevent each peer from receiving discovery data for that VPLS.
- If you manually configure multiple pseudowires and target different IP addresses on the same PE router for each pseudowire, do not use the same virtual circuit identifier (VC ID) to identify the pseudowires terminated at the same PE router.
- You cannot configure a pseudowire by manually configuring a neighbor on one PE router and using autodiscovery on the other PE router to configure the same pseudowire in the other direction.
- Tunnel selection is not supported with autodiscovered neighbors.
- You can have up to 16 route targets only per VFI.
- The same RT is not allowed in multiple VFIs in the same PE router.
- The BGP autodiscovery process does not support dynamic hierarchical VPLS. User-facing PE (U-PE) routers cannot discover the network-facing PE (N-PE) routers, and N-PE routers cannot discover U-PE routers.
- Pseudowires for autodiscovered neighbors are provisioned with split horizon enabled. Therefore, manually configure the pseudowires for hierarchical VPLS. Make sure the U-PE routers do not participate in BGP autodiscovery for those pseudowires.
- Do not disable split horizon on autodiscovered neighbors. Split horizon is required with VPLS Autodiscovery.
- The provisioned peer address must be a /32 address bound to the peer's Label Distribution Protocol (LDP) router ID.
- The peer PE router must be able to access the IP address that is used as the local LDP router ID. Even though the IP address need not be used in the xconnect command on the peer PE router, that IP address must be reachable.
- VPLS Autodiscovery is supported on the Cisco 7600 router hardware. For details on supported shared port adapters and line cards, see the following documents:
Information About VPLS Autodiscovery BGP Based
- How the VPLS Feature Works
- How the VPLS Autodiscovery BGP Based Feature Works
- How Enabling VPLS Autodiscovery Differs from Manually Configuring VPLS
- Show Commands Affected by VPLS Autodiscovery BGP Based
- BGP VPLS Autodiscovery Support on a Route Reflector
How the VPLS Feature Works
VPLS allows Multiprotocol Label Switching (MPLS) networks to provide multipoint Ethernet LAN services, also known as Transparent LAN Services (TLS). All customer sites in a VPLS appear to be on the same LAN, even though those sites might be in different geographic locations.
How the VPLS Autodiscovery BGP Based Feature Works
VPLS Autodiscovery enables each VPLS PE router to discover the other PE routers that are part of the same VPLS domain. VPLS Autodiscovery also tracks when PE routers are added to or removed from the VPLS domain. The autodiscovery and signaling functions use BGP to find and track the PE routers.
BGP uses the L2VPN Routing Information Base (RIB) to store endpoint provisioning information, which is updated each time any Layer 2 VFI is configured. Prefix and path information is stored in the L2VPN database, allowing BGP to make decisions on the best path. When BGP distributes the endpoint provisioning information in an update message to all its BGP neighbors, the endpoint information is used to configure a pseudowire mesh to support L2VPN-based services.
The BGP autodiscovery mechanism facilitates the configuration of L2VPN services, which are an integral part of the Cisco IOS Virtual Private LAN Service (VPLS) feature. VPLS enables flexibility in deploying services by connecting geographically dispersed sites as a large LAN over high-speed Ethernet in a robust and scalable IP MPLS network. For more information about BGP and the L2VPN address family in relation to VPLS Autodiscovery, see the following documents:
How Enabling VPLS Autodiscovery Differs from Manually Configuring VPLS
With VPLS Autodiscovery, you no longer need to manually set up the VPLS. The commands you use to set up VPLS Autodiscovery are similar to those you use to manually configure a VPLS, as shown in the table below. VPLS Autodiscovery uses neighbor commands in L2VPN address family mode to distribute endpoint information to configure a pseudowire.
Table 1 | VPLS Autodiscovery Configuration versus Manual VPLS Configuration |
Manual Configuration of VPLS |
VPLS Autodiscovery: BGP Based |
---|---|
l2 vfi vpls1 manual vpn id 100 neighbor 10.10.10.1 encapsulation mpls neighbor 10.10.10.0 encapsulation mpls exit |
l2 vfi vpls1 autodiscovery vpn id 100 exit router bgp 1 no bgp default ipv4-unicast bgp log-neighbor-changes bgp update-delay 1 neighbor 10.1.1.2 remote-as 1 neighbor 10.1.1.2 update-source Loopback1 . . . address-family l2vpn vpls neighbor 10.1.1.2 activate neighbor 10.1.1.2 send-community extended exit-address-family |
When you configure VPLS Autodiscovery, you enter the l2vfi autodiscovery command. This command allows the VFI to learn and advertise the pseudowire endpoints. As a result, you no longer need to enter the neighbor (VPLS)command in L2 VFI configuration mode.
However, the neighbor (VPLS)command is still supported with VPLS Autodiscovery in L2 VFI command mode. You can use the neighbor (VPLS)command to allow PE routers that do not participate in the autodiscovery process to join the VPLS. You can also use the neighbor (VPLS)command with PE routers that have been configured using the Tunnel Selection feature. You can also use the neighbor (VPLS)command in hierarchical VPLS configurations that have U-PE routers that do not participate in the autodiscovery process and have split-horizon forwarding disabled.
Show Commands Affected by VPLS Autodiscovery BGP Based
VPLS Autodiscovery changes the following show commands:
- The show mpls l2transport vc command with the detail keyword has been updated to include FEC 129 signaling information for the autodiscovered VPLS pseudowires.
- The show vfi command now displays information related to autodiscovered VFIs. The new information includes the VPLS ID, the route distinguisher (RD), the RT, and the router IDs of the discovered peers.
- The show xconnect command has been updated with the rib keyword to provide RIB information about the pseudowires.
BGP VPLS Autodiscovery Support on a Route Reflector
VPLS Autodiscovery is normally run on PE routers to support endpoint discovery and the setup of pseudowires between the PEs (typically a full mesh). VPLS does not normally run on a BGP route reflector. In Cisco IOS Release 12.2(33)SRE, VPLS Autodiscovery support was added to route reflectors. The BGP route reflector can be used to reflect the BGP VPLS prefixes without having VPLS explicitly configured on the route reflector.
The route reflector does not participate in the autodiscovery, meaning that no pseudowires are set up between the route reflector and the PEs. The route reflector reflects the VPLS prefixes to other PEs, so that the PEs do not need to have a full mesh of BGP sessions. The network administrator configures only the BGP VPLS address family on the route reflector. For an example configuration of VPLS autodiscovery support on a route reflector, see the BGP VPLS Autodiscovery Support on Route Reflector Example.
How to Configure VPLS Autodiscovery BGP Based
- Enabling VPLS Autodiscovery BGP Based
- Configuring BGP to Enable VPLS Autodiscovery
- Customizing the VPLS Autodiscovery Settings
Enabling VPLS Autodiscovery BGP Based
Perform the following task to enable each VPLS PE router to discover the other PE routers that are part of the same VPLS domain.
Before configuring VPLS Autodiscovery, perform the Cisco 7600 router-specific tasks listed in the "Virtual Private LAN Services on the Optical Services Modules" chapter in the Cisco 7600 Series Router Cisco IOS Software Configuration Guide , Release 12.2SR.
DETAILED STEPS
Configuring BGP to Enable VPLS Autodiscovery
In Cisco IOS Release 12.2(33)SRB, the BGP L2VPN address family was introduced with a separate L2VPN RIB that contains endpoint provisioning information for VPLS Autodiscovery. BGP learns the endpoint provisioning information from the L2VPN database which is updated each time a Layer 2 virtual forwarding instance (VFI) is configured. When BGP distributes the endpoint provisioning information in an update message to all its BGP neighbors, the endpoint information is used to configure a pseudowire mesh to support aL2VPN-based services.
DETAILED STEPS
Customizing the VPLS Autodiscovery Settings
Several commands allow you to customize the VPLS environment. You can specify identifiers for the VPLS domain, the route distinguisher, the route target, and the PE router. Perform the following steps to customize these settings.
DETAILED STEPS
Command or Action | Purpose | |
---|---|---|
|
Example: Router> enable |
Enables privileged EXEC mode.
|
|
Example: Router# configure terminal |
Enters global configuration mode. |
|
Example: Router(config)# l2 vfi vpls1 autodiscovery |
Enables VPLS Autodiscovery on the PE router and enters L2 VFI configuration mode. |
|
Example: Router(config-vfi)# vpn id 10 |
Configures a VPN ID for the VPLS domain. |
|
Example: Router(config-vfi)# vpls-id 5:300 |
(Optional) Specifies the VPLS domain. This command is optional, because VPLS Autodiscovery automatically generates a VPLS ID using the BGP autonomous system number and the configured VFI VPN ID. You can use this command to change the automatically generated VPLS ID. There are two formats for configuring the VPLS ID argument. It can be configured in the autonomous-system-number:network number (ASN:nn) format, as shown in the example, or it can be configured in the IP-address:network number format (IP-address:nn). |
|
Example: Router(config-vfi)# rd 2:3 |
(Optional) Specifies the RD to distribute endpoint information. This command is optional, because VPLS Autodiscovery automatically generates an RD using the BGP autonomous system number and the configured VFI VPN ID. You can use this command to change the automatically generated route distinguisher. There are two formats for configuring the route distinguisher argument.It can be configured in the autonomous-system-number:network number (ASN:nn) format, as shown in the example, or it can be configured in the IP-address:network number format (IP-address:nn). |
|
Example: Router(config-vfi)# route-target 600:2222 |
(Optional) Specifies the route target (RT). This command is optional, because VPLS Autodiscovery automatically generates a route target using the lower 6 bytes of the RD and VPLS ID. You can use this command to change the automatically generated route target. There are two formats for configuring the route target argument. It can be configured in the autonomous-system-number:network number (ASN:nn) format, as shown in the example, or it can be configured in the IP-address:network number format (IP-address:nn). |
|
Example: Router(config-vfi)# l2 router-id 10.10.10.10 |
(Optional) Specifies a unique identifier for the PE router. This command is optional, because VPLS Autodiscovery automatically generates a Layer 2 router ID using the MPLS global router ID. You can use this command to change the automatically generated ID. |
|
Example: Router(config-vfi)# exit |
Exits L2 VFI configuration mode. Commands take effect after the router exits L2 VFI configuration mode. |
Configuration Examples for VPLS Autodiscovery BGP Based
The following examples shows the configuration of a network using VPLS Autodiscovery and VPLS Autodiscovery supported on a route reflector:
- VPLS Autodiscovery BGP Based Basic Example
- BGP VPLS Autodiscovery Support on Route Reflector Example
VPLS Autodiscovery BGP Based Basic Example
The figure below show a basic configuration of VPLS Autodiscovery.
Figure 1 | Basic VPLS Autodiscovery Configuration |
PE1
l2 router-id 10.1.1.1 l2 vfi auto autodiscovery vpn id 100 ! pseudowire-class mpls encapsulation mpls ! interface Loopback1 ip address 10.1.1.1 255.255.255.255 ! interface Ethernet0/0 description Backbone interface ip address 192.168.0.1 255.255.255.0 mpls ip ! router ospf 1 log-adjacency-changes network 10.1.1.0 0.0.0.255 area 0 network 172.16.0.0 0.0.0.255 area 0 ! router bgp 1 no bgp default ipv4-unicast bgp log-neighbor-changes bgp update-delay 1 neighbor 10.1.1.2 remote-as 1 neighbor 10.1.1.2 update-source Loopback1 neighbor 10.1.1.3 remote-as 1 neighbor 10.1.1.3 update-source Loopback1 ! address-family ipv4 no synchronization no auto-summary exit-address-family ! address-family l2vpn vpls neighbor 10.1.1.2 activate neighbor 10.1.1.2 send-community extended neighbor 10.1.1.3 activate neighbor 10.1.1.3 send-community extended exit-address-family
PE2
l2 router-id 10.1.1.2 l2 vfi auto autodiscovery vpn id 100 ! pseudowire-class mpls encapsulation mpls ! interface Loopback1 ip address 10.1.1.2 255.255.255.255 ! interface Ethernet0/0 description Backbone interface ip address 192.168.0.2 255.255.255.0 mpls ip ! router ospf 1 log-adjacency-changes network 10.1.1.0 0.0.0.255 area 0 network 172.16.0.0 0.0.0.255 area 0 ! router bgp 1 no bgp default ipv4-unicast bgp log-neighbor-changes bgp update-delay 1 neighbor 10.1.1.1 remote-as 1 neighbor 10.1.1.1 update-source Loopback1 neighbor 10.1.1.3 remote-as 1 neighbor 10.1.1.3 update-source Loopback1 ! address-family ipv4 no synchronization no auto-summary exit-address-family ! address-family l2vpn vpls neighbor 10.1.1.1 activate neighbor 10.1.1.1 send-community extended neighbor 10.1.1.3 activate neighbor 10.1.1.3 send-community extended exit-address-family
PE3
l2 router-id 10.1.1.3 l2 vfi auto autodiscovery vpn id 100 ! pseudowire-class mpls encapsulation mpls ! interface Loopback1 ip address 10.1.1.3 255.255.255.255 ! interface Ethernet0/0 description Backbone interface ip address 192.168.0.3 255.255.255.0 mpls ip ! router ospf 1 log-adjacency-changes network 10.1.1.0 0.0.0.255 area 0 network 172.16.0.0 0.0.0.255 area 0 ! router bgp 1 no bgp default ipv4-unicast bgp log-neighbor-changes bgp update-delay 1 neighbor 10.1.1.1 remote-as 1 neighbor 10.1.1.1 update-source Loopback1 neighbor 10.1.1.2 remote-as 1 neighbor 10.1.1.2 update-source Loopback1 ! address-family ipv4 no synchronization no auto-summary exit-address-family ! address-family l2vpn vpls neighbor 10.1.1.1 activate neighbor 10.1.1.1 send-community extended neighbor 10.1.1.2 activate neighbor 10.1.1.2 send-community extended exit-address-family
BGP VPLS Autodiscovery Support on Route Reflector Example
In the following example, a host named PE-RR (indicating Provider Edge-Route Reflector) is configured as a route reflector capable of reflecting VPLS prefixes. The VPLS address family is configured by address-family l2vpn vpls below.
hostname PE-RR ! router bgp 1 bgp router-id 1.1.1.3 no bgp default route-target filter bgp log-neighbor-changes neighbor iBGP_PEERS peer-group neighbor iBGP_PEERS remote-as 1 neighbor iBGP_PEERS update-source Loopback1 neighbor 1.1.1.1 peer-group iBGP_PEERS neighbor 1.1.1.2 peer-group iBGP_PEERS ! address-family l2vpn vpls neighbor iBGP_PEERS send-community extended neighbor iBGP_PEERS route-reflector-client neighbor 1.1.1.1 peer-group iBGP_PEERS neighbor 1.1.1.2 peer-group iBGP_PEERS exit-address-family
Additional References
The following sections provide references related to the VPLS Autodiscovery: BGP Based feature.
Related Documents
Related Topic |
Document Title |
---|---|
Virtual Private LAN Services on the Cisco 7600 series router |
"Virtual Private LAN Services on the Optical Services Modules" chapter in the Cisco 7600 Series Router Cisco IOS Software Configuration Guide , Release 12.2SR |
L2 VPNs on the Cisco 7600 router |
Configuration information for Layer 2 VPNs on the Cisco 7600 router is included in the following documents:
|
MPLS Commands |
Cisco IOS Multiprotocol Label Switching Command Reference |
Standards
Standard |
Title |
---|---|
draft-ietf-l2vpn-signaling-08.txt |
Provisioning, Autodiscovery, and Signaling in L2VPNs |
draft-ietf-l2vpn-vpls-bgp-08.8 |
Virtual Private LAN Service (VPLS) Using BGP for Autodiscovery and Signaling |
draft-ietf-mpls-lsp-ping-03.txt |
Detecting MPLS Data Plane Failures |
draft-ietf-pwe3-vccv-01.txt |
Pseudo-Wire (PW) Virtual Circuit Connection Verification (VCCV) |
MIBs
MIB |
MIBs Link |
---|---|
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
RFC |
Title |
---|---|
RFC 3916 |
Requirements for Pseudo-wire Emulation Edge-to-Edge (PWE3) |
RFC 3981 |
Pseudo Wire Emulation Edge-to-Edge Architecture |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register on Cisco.com. |
Feature Information for VPLS Autodiscovery BGP Based
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 2 | Feature Information for VPLS Autodiscovery: BGP Based |
Feature Name |
Releases |
Feature Information |
---|---|---|
VPLS Autodiscovery: BGP Based |
12.2(33)SRB |
VPLS Autodiscovery enables each Virtual Private LAN Service (VPLS) provider edge (PE) router to discover which other PE routers are part of the same VPLS domain. In 12.2(33)SRB, this feature was introduced on the Cisco 7600 router. The following commands were introduced or modified for this feature:
|
BGP VPLS Autodiscovery Support on Route Reflector |
12.2(33)SRE |
This feature was introduced on the Cisco 7600 series routers. This feature is documented in the following sections: |
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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.