[j-nsp] Q-In-Q using M7i and CISCO Switch

[sthaug at nethelp.no]

>   We need to pass 20 different vlans using only the 3 ones that carrier 
> provide to us.
> 
> First 10 vlans need to terminate in a L3 interface inside the router 
> with an IP address.

So, assuming you use carrier (outer) VLAN 100 for this, something like
the following:

interfaces {
 ge-0/0/0 {
  flexible-vlan-tagging;
  encapsulation flexible-ethernet-services;
  unit 1 {
   vlan-tags outer 100 inner 1;
   family inet {
    address ...
  }
  unit 2 {
   vlan-tags outer 100 inner 2;
   family inet {
    address ...
  }
  ...
 }
}

> Other 10 we need to pop from the IQ2E interface and let it free using a 
> L2 switch

Assuming you use carrier (outer) VLAN 200 for this, and the traffic is
sent out again on ge-0/1/0, using "interface-switch":

interfaces {
 ge-0/0/0 {
  flexible-vlan-tagging;
  encapsulation flexible-ethernet-services;
  unit 11 {
   encapsulation vlan-ccc;
   vlan-tags outer 200 inner 11;
   input-vlan-map pop;
   output-vlan-map push;
  }
  unit 12 {
   encapsulation vlan-ccc;
   vlan-tags outer 200 inner 12;
   input-vlan-map pop;
   output-vlan-map push;
  }
  ...
 }
}

interfaces {
 ge-0/1/0 {
  flexible-vlan-tagging;
  encapsulation flexible-ethernet-services;
  unit 11 {
   encapsulation vlan-ccc;
   vlan-id 11;
  }
  unit 12 {
   encapsulation vlan-ccc;
   vlan-id 12;
  }
  ...
 }
}

protocols {
 connections {
  interface-switch sw11 {
   interface ge-0/0/0.11;
   interface ge-0/1/0.11;
  }
  interface-switch sw12 {
   interface ge-0/0/0.12;
   interface ge-0/1/0.12;
  }
  ...
 }
}

As you can see a Juniper M7i isn't really well suited for L2
switching (the syntax is clumsy and the ports are expensice) - but
I believe it should work.

You'll need to set the interface MTU, and you'll also need MPLS
configuration on the router if you want to use interface-switch,
as far as I can remember. Might be simpler to connect a normal L2
switch to the trunk from the carrier, and use that switch to pop
off the outer VLAN.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no