[c-nsp] L2 over L3 scenario

[James Bensley]

On 23 October 2015 at 09:37, james list <jameslist72 at gmail.com> wrote:
>
> Which are current Cisco device supporting L2TPv3 ?
>
>
> I’d like to share experience, receive suggestions if any, alternatives if
> any, recommendations, scalability numbers if any, etc.

L2TPv3 works fairly well (better than I expected). I did some lab
testing on it last year before deploying it for a customer where I had
no other choice. I'd always pushed it to the side in favour of MPLS
pseudowires and prior to last year I had only used it where I had to
and the requirement was minimal (minimal traffic volume).

Last year I had a customer than needed multiple 100Mbps L2 links for
backing up data using a layer 2 application/service. Any typical Cisco
ISRG2 like will process L2TPv3 in hardware so I dropped some 1941's in
and it "just worked". They max out their 100Mbps fibres ever night
with L2TPv3 tunnels between sites.

If you use port based L2TPv3 tunnels on the built in interfaces they
do support the forwarding of layer 2 control frames too, so
spanning-tree, CDP, LAG/LACP, UDLD etc also work. I'm now about to
deliver this again possibly with 2921s for higher throughput for
another customer and this customer will be runing STP or LACP, we've
tested both in the lab and the different failure scenarios and it all
"just works". They can just add additional VLANs on their switch
trunks facing the 2921s and extend extra VLANs between sites without
input from me, port based if ignorant and just transport whatever it
recieves.

My only gripe is no layer 2 QoS.

Cheers,
James.