Configuring VPLS Instances with BGP Signaling

You must configure a VPLS instance for each VPLS domain in which the router participates. From a configuration standpoint, a VPLS instance is simply a new or existing bridge group that you configure with additional VPLS attributes.

Table 1 lists the commands that you use to configure a basic VPLS instance, as described in this section.

To configure a basic VPLS instance with BGP signaling on the PE router:

1. From Global Configuration mode, create the VPLS instance by specifying the transport virtual router for this instance.

   host1(config)#bridge customer1 vpls transport-virtual-router vr1

    

   If the bridge group you specify (customer1 in this example) already exists on the router, issuing this command causes the bridge group to become a VPLS instance.

   Note: To configure a VPLS instance, you must issue the bridge vpls transport-virtual-router command before you issue any of the other bridge vpls commands in this procedure. If the bridge vpls transport-virtual-router command is not issued first, the other bridge vpls commands fail.

2. Specify the maximum number of customer sites that can participate in the VPLS domain represented by the VPLS instance. (By default, a VPLS domain must consist of at least one site.)
   host1(config)#bridge customer1 vpls site-range 15
3. Specify a name and unique identifier for the customer site that belongs to the VPLS instance.
   host1(config)#bridge customer1 vpls site-name westford site-id 1

   The site ID value must be greater than zero and be unique across the VPLS domain. This is not true for a multihomed customer site. See Configuring BGP Multihoming for VPLS for more information.

4. Specify the unique, two-part route distinguisher (RD) for the VPLS instance.
   host1(config)#bridge customer1 vpls rd 100:11

   In this example, the first number in the route distinguisher (100) is the number of the AS in which the extended community resides. The second number in the route distinguisher (11) uniquely identifies the VPLS instance within the AS.

   Tip: You cannot change or remove the route distinguisher for a VPLS instance after you set it; for this reason the no bridge vpls rd command fails. . To change the route distinguisher, you must either remove the transport virtual router configuration from the VPLS instance or delete the VPLS instance from the router. You can then reconfigure the VPLS instance with a new route distinguisher.

5. Create or add a route target to the import and export lists of VPN extended communities for this VPLS instance.
   host1(config)#bridge customer1 vpls route-target both 100:1

   The PE router uses the lists of VPN extended communities to determine which routes are imported by this VPLS instance.

   Best Practice: We recommend that you add the route target to both the VPLS instance's import list and export list of VPN extended communities. To do so, use the both keyword.

Multiple VPLS instances that use the same transport virtual router cannot have the same route distinguisher. Conversely, multiple VPLS instances that use different transport virtual routers can have the same route distinguisher.

For example, the following commands configure the transport virtual router for each of three VPLS instances: vplsA, vplsB, and vplsC. The transport virtual router for both vplsA and vplsC is vr1, and the transport virtual router for vplsB is vr2.

Because vplsA and vplsC use the same transport virtual router, vr1, you cannot assign them the same route distinguisher. Consequently, the following operation fails, and the router displays an error message.

However, both vplsA and vplsB can use the same route distinguisher because their transport virtual routers are different. Consequently, the following commands are valid.