Using the Layer 2 Interworking Interface to Interconnect a Layer 2 VPN to a Layer 2 VPN
Instead of using a physical Tunnel PIC for looping the packet received from the Layer 2 VPN to another Layer 2 VPN, the Layer 2 Interworking interface uses Junos OS to stitch together both Layer 2 VPN routes.
To configure the interworking interface, include the iw0 statement. The iw0 statement is configured at
the [edit interfaces] hierarchy level.
[edit interfaces]
iw0 {
unit 0 {
peer 1;
}
unit 1 {
peer 0;
}
}
You must always create and delete (or deactivate) interworking (iw) interfaces in pairs, such as:
set interfaces iw0 unit 0 peer-unit 1 set interfaces iw0 unit 1 peer-unit 0
An error message displays if you delete or deactivate only one of the interworking interfaces. To successfully deactivate the interfaces and avoid any configuration errors, you must deactivate both.
The configuration of an interworking (iw) interface is
similar to the configuration of a logical tunnel (lt) interface. In
this example, the logical interfaces must be associated with the endpoints
of both Layer 2 VPN connections terminating on this router. To make
the association, include the interfaces statement and specify iw0 as the interface name. Include the statement at the [edit routing-instances routing-instances-name protocols l2vpn site site-name] hierarchy
level for each routing instance. The routing-instances statement
is configured at the [edit routing-instances] hierarchy
level.
[edit routing-instances]
L2VPN-PE1 {
instance-type l2vpn;
interface iw0.0;
route-distinguisher 65000:3;
vrf-target target:65000:2;
protocols {
l2vpn {
encapsulation-type ethernet;
site CE3 {
site-identifier 3;
interface iw0.0 {
remote-site-id 1;
}
}
}
}
}
L2VPN-PE5 {
instance-type l2vpn;
interface iw0.1;
route-distinguisher 65000:33;
vrf-target target:65000:2;
protocols {
l2vpn {
encapsulation-type ethernet;
site CE3 {
site-identifier 3;
interface iw0.1 {
remote-site-id 5;
}
}
}
}
}
In addition to the iw0 interface configuration,
Layer 2 interworking l2iw protocols need to be configured.
Without the l2iw configuration, the l2iw routes
will not be formed, regardless of whether any iw interfaces
are present. Only standard trace options can be configured within
the l2iw protocol. The minimum configuration necessary for the feature
to work is shown below:
[edit]
protocols {
l2iw;
}