[j-nsp] GRE on MX960

[sthaug at nethelp.no]

> DPC(E) needs to spend entire PFE for tunneling, all front-plate ports
> on that PFE will be disabled.
> 
> MPC can do tunneling without dedicating PFE for it.
> 
> I'm sure it's documented somewhere.

https://www.juniper.net/documentation/en_US/junos/topics/example/chassis-tunnel-interfaces-10-gigabit-ethernet-4-port-dpc-configuring.html

"Ethernet and tunnel interfaces cannot coexist on the same Packet
Forwarding Engine of a 10-Gigabit Ethernet 4-port DPC."

I *thought* I remembered that you would disable just one of the 10G
ports. But the above description is pretty clear.

Compare with the description for the 40 x 1G DPC:

https://www.juniper.net/documentation/en_US/junos/topics/example/chassis-tunnel-interfaces-gigabit-ethernet-40-port-dpc-configuring.html

"On a Gigabit Ethernet 40-port DPC, tunnel interfaces coexist with
Ethernet interfaces."

Steinar Haug, Nethelp consulting, sthaug at nethelp.no