[j-nsp] VPLS issue...

[Derick Winkworth]

I found three ways to keep the local interface up so it can hit the irb 
interface even if all remote PEs for the VPLS instance are lost:



1.  Use two physical ports to the PE from the CE, one for VPLS and one for L3. 
You could put a switch in front of your PE to accomplish this.  I think this is 
the cleanest way.

2.  Plug a cable into two ports on the same PE (both ends of cable going into 
same box).  Build a bridge-group for the VLAN.  Put one end of the cable into 
the bridge group.  In the same bridge-group put the VLAN coming in from the CE.  
The other end of the cable put into the VPLS switch instance.  Traffic coming 
from CE will be bridged to the one end of the cable then come back around into 
the VPLS instance.  The irb interface is specified in the bridge-group.  The irb 
interface can exist in any routing-instance.

3.  Make an lt-x/x/x interface pair.  Build a bridge-group for the VLAN, put the 
VLAN coming from the CE into the bridge-group.  Put one of the lt interfaces 
into the bridge group.  This lt interface should be "encapsulation vlan".  The 
other lt interface should be "encapsulation vlan-vpls" and put this into the 
VPLS instance.  The irb interface is specified in the bridge-group.  The irb 
interface can exist in any routing-instance.