Configuring A-VPLS

This chapter describes how to configure Layer 2 Virtual Private Networks (L2VPN) Advanced Virtual Private LAN Services (A-VPLS). Release 12.2(33)SXI4 and later releases support A-VPLS.

Note For complete syntax and usage information for the commands used in this chapter, see the Cisco IOS Master Command List, at this URL:

http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html

This chapter consists of these sections:

•Understanding A-VPLS

•Restrictions for A-VPLS

•Configuring A-VPLS

Tip For additional information about Cisco Catalyst 6500 Series Switches (including configuration examples and troubleshooting information), see the documents listed on this page:

http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html

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Understanding A-VPLS

A-VPLS introduces the following enhancements to VPLS:

•Ability to load-balance traffic at the provider edge (PE) among multiple equal-cost core-facing paths and at core interfaces using flow labels.

•Support for redundant PE routers.

A-VPLS uses the Flow Aware Transport (FAT) Pseudowire feature to achieve PE redundancy and load-balancing on both PE and core routers. FAT pseudowires are used to load-balance traffic in the core when equal cost multipaths are used. The PE router adds an additional MPLS Label to the each packet (the flow label). Each flow has a unique flow label. For more information about FAT pseudowires, see PWE3 Internet-Draft Flow Aware Transport of MPLS Pseudowires (draft-bryant-filsfils-fat-pw).

Restrictions for A-VPLS

•Release 12.2(33)SXJ1 and later releases support configuration of ES+ module ports as MPLS PE core-facing ports that carry A-VPLS traffic.

•Release 12.2(33)SXI4a and later releases support A-VPLS on these core facing port types in a 7600-SIP-400:

–Gigabit and 10-Gigabit Ethernet SPAs (2X1GE-V1, 2X1GE-V2 and 1X10GE-V2 SPA)

–Packet over Sonet (POS) SPAs (2XOC3, 4XOC3, 1XOC12 and 1XOC48 )

•Release 12.2(33)SXI4a and later releases support these types of configurations:

–MPLS core with configuration of PE routers through the neighbor command under transport vpls mode.

–MPLS core with configuration of PE routers through MPLS traffic engineering tunnels using explicit paths.

–IP core with configuration of PE routers through MPLS over GRE tunnels.

Other configuration methods, including use of the route-via command, BGP autodiscovery, or explicit VLAN assignment to a PE egress port, are not supported.

•A-VPLS supports the following:

–In switches without an ES+ line card:

—Up to 32 EtherChannel port-channel interfaces.  (ES+ line cards do not support port-channel interfaces)

—Up to 60 VPLS neighbors, minus the number of neighbors configured with the  load-balance flow command.

–In switches with an ES+ line card (with or without a 7600-SIP-400):

—Up to 30 EtherChannel port-channel interfaces.  (ES+ line cards do not support port-channel nterfaces)

—Up to 30 VPLS neighbors, minus the number of neighbors configured with the  load-balance flow command.

•A-VPLS requires nonstop forwarding and stateful switchover.

•A-VPLS works with following:

–MPLS Traffic Engineering tunnels that are configured with explicit paths.

–Generic Routing Encapsulation (GRE tunnels) that are configured with static routes to the tunnel destination.

For information about MPLS traffic engineering and GRE tunnels, see the following documents:

–MPLS Traffic Engineering and Enhancements

–Implementing Tunnels

•The ping and traceroute commands that support the Any Transport over MPLS Virtual Circuit Connection Verification (VCCV) feature are not supported over FAT pseudowires.

•The VPLS Autodiscovery feature is not supported with A-VPLS.

•Load-balancing is not supported in the core routers when the core uses IP to transport packets.

Configuring A-VPLS

The following sections explain how to configure A-VPLS:

•Enabling Load-Balancing with ECMP and FAT Pseudowires (Required)

•Enabling Port-Channel Load-Balancing (Required)

•Explicitly Specifying the PE Routers As Part of Virtual Ethernet Interface Configuration (Optional)

•Configuring an MPLS Traffic Engineering Tunnel (Optional)

•Configuring a GRE Tunnel (Optional)

Enabling Load-Balancing with ECMP and FAT Pseudowires

The following steps explain how to configure load-balancing on the provider edge (PE) routers, which enables it on the core P routers. No configuration is required on the core P routers.

To enable load-balancing on the edge routers, issue the load-balance flow command. The load-balancing rules are configured through the port-channel load-balance command parameters (see the "Enabling Port-Channel Load-Balancing" section).

To enable core load-balancing, issue the flow-label enable command on both PE routers. You must issue the load-balance flow command with the flow-label enable command.

 
Command
Purpose

Step 1 

Router> enable

Enables privileged EXEC mode (enter your password if prompted).

Step 2 

Router# configure terminal

Enters global configuration mode.

Step 3 

Router(config)# pseudowire-class name

Establishes a pseudowire class with a name that you specify and enters pseudowire class configuration mode.

Step 4 

Router(config-pw)# encapsulation mpls

Specifies the MPLS tunneling encapsulation type.

Step 5 

Router(config-pw)# load-balance flow

Enables load-balancing on ECMPs.

Step 6 

Router(config-pw)# flow-label enable

Enables the imposition and disposition of flow labels for the pseudowire.

Step 7 

Router(config-pw)# end

Exits pseudowire class configuration mode and enters privileged EXEC mode.

Enabling Port-Channel Load-Balancing

The following task explains how to enable port channel load-balancing, which sets the load-distribution method among the ports in the bundle. If the port-channel load-balance command is not configured, load-balancing occurs with default parameters.

 
Command
Purpose

Step 1 

Router> enable

Enables privileged EXEC mode. Enter your password if prompted.

Step 2 

Router# configure terminal

Enters global configuration mode.

Step 3 

Router(config)# port-channel load-balance method

Specifies the load distribution method among the ports in a bundle.

Step 4 

Router(config)# exit

Exits global configuration mode and enters privileged EXEC mode.

Explicitly Specifying the PE Routers As Part of Virtual Ethernet Interface Configuration

There are several ways to specify the route through which traffic should pass.

•Explicitly specify the PE routers as part of the virtual Ethernet interface configuration

•Configure an MPLS Traffic Engineering tunnel

•Configure a GRE tunnel

The following task explains how to explicitly specify the PE routers as part of the virtual Ethernet interface configuration.

 
Command
Purpose

Step 1 

Router> enable

Enables privileged EXEC mode. Enter your password if prompted.

Step 2 

Router# configure terminal

Enters global configuration mode.

Step 3 

Router(config)# interface virtual-ethernet num

Creates a virtual Ethernet interface and enters interface configuration mode.

Step 4 

Router(config-if)# transport vpls mesh

Create a full mesh of pseudowires and enters VPLS transport mode.

Step 5 

Router(config-if-transport)# neighbor remote-router-id [pw-class pw-class-name]

Specifies the PE routers to be used in the pseudowire.

Step 6 

Router(config-if-transport)# exit

Exits VPLS transport configuration mode and enters interface configuration mode.

Step 7 

Router(config-if)# switchport

Configures the port for Layer 2 switching.

Step 8 

Router(config-if)# switchport mode trunk

Enables permanent trunking mode and negotiates to convert the link into a trunk link.

Step 9 

Router(config-if)# switchport trunk allowed vlan {add | except | none | remove} vlan [,vlan[,vlan[,...]]

Configures the list of VLANs allowed on the trunk.

Step 10 

Router(config)# exit

Exits interface configuration mode and enters privileged EXEC mode.

Configuring an MPLS Traffic Engineering Tunnel

There are several ways to specify the route through which traffic should pass.

•Explicitly specify the PE routers as part of the virtual Ethernet interface configuration

•Configure an MPLS Traffic Engineering tunnel

•Configure a GRE tunnel

The following task explains how to configure an MPLS Traffic Engineering tunnel. For more information about MPLS Traffic Engineering tunnels, see MPLS Traffic Engineering and Enhancements.

 
Command
Purpose

Step 1 

Router> enable

Enables privileged EXEC mode (enter your password if prompted).

Step 2 

Router# configure terminal

Enters global configuration mode.

Step 3 

Router(config)# interface tunnel number

Configures an interface type and enters interface configuration mode.

Step 4 

Router(config-if)# ip unnumbered type number

Assigns an IP address to the tunnel interface. An MPLS traffic engineering tunnel interface should be unnumbered because it represents a unidirectional link.

Step 5 

Router(config-if)# tunnel destination ip-address

Specifies the destination for a tunnel. The ip-address keyword is the IP address of the host destination expressed in dotted decimal notation.

Step 6 

Router(config-if)# tunnel mode mpls traffic-eng

Configures the tunnel encapsulation mode to MPLS traffic engineering.

Step 7 

Router(config-if)# tunnel mpls traffic-eng autoroute announce

Configures the IGP to use the tunnel in its enhanced SPF calculation.

Step 8 

Router(config-if)# tunnel mpls traffic-eng path-option number {dynamic | explicit {name path-name} | identifier path-number} [lockdown]

Configures the tunnel to use a named IP explicit path or a path dynamically calculated from the traffic engineering topology database. A dynamic path is used if an explicit path is currently unavailable.

Step 9 

Router(config-if)# exit

Exits interface configuration mode and returns to privileged EXEC mode.

Configuring a GRE Tunnel

There are several ways to specify the route through which traffic should pass.

•Explicitly specify the PE routers as part of the virtual Ethernet interface configuration

•Configure an MPLS Traffic Engineering tunnel

•Configure a GRE tunnel

The following task explains how to configure a GRE tunnel. For more information on GRE tunnels, see Implementing Tunnels.

 
Command
Purpose

Step 1 

Router> enable

Enables privileged EXEC mode. Enter your password if prompted.

Step 2 

Router# configure terminal

Enters global configuration mode.

Step 3 

Router(config)# interface type number

Specifies the interface type and number and enters interface configuration mode. To configure a tunnel, use tunnel for the type argument.

Step 4 

Router(config-if)# tunnel mode {gre ip | gre multipoint}

Specifies the encapsulation protocol to be used in the tunnel.

Step 5 

Router(config-if)# mpls ip

Enables MPLS on the tunnel.

Step 6 

outer(config-if)# tunnel source {ip-address | interface-type interface-number}

Configures the tunnel source.

•Use the ip-address argument to specify the source IP address.

•Use the interface-type and interface-number arguments to specify the interface to use.

Note The tunnel source and destination IP addresses must be defined on both PE routers.

Step 7 

Router(config-if)# tunnel destination {hostname | ip-address}

Configures the tunnel destination.

•Use the hostname argument to specify the name of the host destination.

•Use the ip-address argument to specify the IP address of the host destination.

Note The tunnel source and destination IP addresses must be defined on both PE routers.

Step 8 

Router(config-if)# exit

Exits interface configuration mode and returns to privileged EXEC mode.

Step 9 

Router(config)# ip route ip-address tunnel num

Creates a static route.

These examples show the three supported methods of configuring A-VPLS.

Explicitly Specifying Peer PE Routers

The following example shows how to create two VPLS domains under VLANs 10 and 20. Each VPLS domain includes two pseudowires to peer PE routers 10.2.2.2 and 10.3.3.3. Load-balancing is enabled through the load-balance flow and flow-label enable commands. 

pseudowire-class cl1 

   encap mpls 

   load-balance flow 

   flow-label enable 

!

port-channel load-balance src-mac 

!

interface virtual-ethernet 1

   transport vpls mesh

      neighbor 10.2.2.2 pw-class cl1 

      neighbor 10.3.3.3 pw-class cl1 

   switchport

   switchport mode trunk

   switchport trunk allowed vlan 10, 20

Using MPLS Traffic Engineering Tunnels

The following example shows the creation of two VPLS domains and uses MPLS Traffic Engineering tunnels to specify the explicit path. 

pseudowire-class cl1 

   encap mpls

   load-balance flow 

   flow-label enable 

!

port-channel load-balance src-mac 

!

interface Tunnel1

   ip unnumbered Loopback0

   tunnel mode mpls traffic-eng

   tunnel destination 192.168.1.1

   tunnel mpls traffic-eng autoroute announce

   tunnel mpls traffic-eng path-option 1 explicit name LSP1

!

ip explicit-path name LSP1 enable

   next-address 192.168.2.2

   next-address loose 192.168.1.1

!

interface Tunnel2

   ip unnumbered Loopback0

   tunnel mode mpls traffic-eng

   tunnel destination 172.16.1.1

   tunnel mpls traffic-eng autoroute announce

   tunnel mpls traffic-eng path-option 1 explicit name LSP2

!

ip explicit-path name LSP2 enable

   next-address 172.16.2.2

   next-address loose 172.16.1.1

!

interface virtual-ethernet 1

    transport vpls mesh 

      neighbor 10.2.2.2 pw-class cl1 

      neighbor 10.3.3.3 pw-class cl1 

   switchport 

   switchport mode trunk

   switchport trunk allowed vlan 10,20

Using MPLS over GRE Tunnels

The following example shows the creation of two VPLS domains under VLANs 10 and 20. Each VPLS domain includes two pseudowires to peer PEs 10.2.2.2 and 10.3.3.3. The pseudowires are MPLS over GRE tunnels because the core is IP. 

pseudowire-class cl1 

   encap mpls

   load-balance flow

!

port-channel load-balance src-mac 

!

interface tunnel 1

   tunnel mode gre ip

   mpls ip 

   tunnel source 10.1.1.1

   tunnel destination 10.2.2.2

!

interface tunnel 2

   tunnel mode gre ip

   mpls ip 

   tunnel source 10.1.1.1

   tunnel destination 10.3.3.3

!

interface virtual-ethernet 1

   transport vpls mesh 

      neighbor 10.2.2.2 pw-class cl1 

      neighbor 10.3.3.3 pw-class cl1 

   switchport 

   switchport mode trunk

   switchport trunk allowed vlan 10, 20

 
   
 
    
   
 
    
ip route 10.2.2.2 255.255.255.255 Tunnel1

 
   
 
    
   
 
    
ip route 10.3.3.3 255.255.255.255 Tunnel2

 
   
 
     
     
    
   
 Routed Pseudo-Wire (RPW) and Routed VPLS 
 
    
   
 RPW and Routed VPLS can route Layer 3 traffic as well as switch Layer 2 frames for pseudowire connections between provider edge (PE) devices. Both point-to-point PE connections, in the form of Ethernet over MPLS (EoMPLS), and Virtual Private LAN Services (VPLS) multipoint PE connections are supported. The ability to route frames to and from these interfaces supports termination of a pseudowire into a Layer 3 network (VPN or global) on the same switch, or to tunnel Layer 3 frames over a Layer 2 tunnel (EoMPLS or VPLS). The feature supports faster network convergence in the event of a physical interface or device failure through the MPLS Traffic Engineering (MPLS-TE) and Fast Reroute (FRR) features. In particular, the feature enables MPLS TE-FRR protection for Layer 3 multicast over a VPLS domain. 
 
   
 
     
   
 
   
 
    
   
 Note When the RPW is configured in A-VPLS mode, TE/FRR is not supported because A-VPLS runs over ECMP and the ECMP convergence is comparable to TE/FRR. 
 
   
 
    
   
 To configure routing support for the pseudowire, configure an IP address and other Layer 3 features for the Layer 3 domain (VPN or global) in the virtual LAN (VLAN) interface configuration. The following example assigns the IP address 10.10.10.1 to the VLAN 100 interface, and enables Multicast PIM. (Layer 2 forwarding is defined by the VFI VFI100.) 
 
    
   
 
    
interface vlan 100 

 
   
 
    
   
 
    
  xconnect vfi VFI100 

 
   
 
    
   
 
    
  ip address 10.10.10.1 255.255.255.0 

 
   
 
    
   
 
    
  ip pim sparse-mode 

 
   
 
    
   
 
    
 
   
 
    
   
 The following example assigns an IP address 20.20.20.1 of the VPN domain VFI200. (Layer 2 forwarding is defined by the VFI VFI200.) 
 
    
   
 
    
interface vlan 200 

 
   
 
    
   
 
    
  xconnect vfi VFI200 

 
   
 
    
   
 
    
  ip vrf forwarding VFI200 

 
   
 
    
   
 
    
  ip address 20.20.20.1 255.255.255.0