[j-nsp] vpls loop avoidance

[Keegan Holley]

I'm trying to get my handle on vpls loop avoidance and I can't remember the
default behavior regarding site-id's and node-id's.  I remember reading
about it in one config guide or another but I can't seem to find it now.
I'm trying to remember if broadcast, multicast and unknown unicast is
flooded between PE router interfaces with the same site id's and maybe just
some general guidelines on their behavior.  I'm trying to understand best
practices for loop avoidance.  It seems to loop with any standards based STP
protocol if two or more interfaces are connected to routers configured with
the same site-id.  The behavior I see seems to be the opposite of what the
website says.

http://www.juniper.net/techpubs/en_US/junos10.4/topics/concept/vpn-configuring-ethernet-switch-as-the-ce-device.html