[c-nsp] QinQ on 3550 not working?

[Tony]

Hi Simon,


--- On Thu, 20/1/11, Simon Lockhart <simon at slimey.org> wrote:

---snip--

> When the Customer site switch is a 3560, I can "ping
> 172.30.1.1" and
> "ping vrf network2 172.40.1.1" without problem.
> 
> When the Customer site switch is a 3550, I can "ping
> 172.30.1.1" fine, but
> trying to "ping vrf network2 172.40.1.1" results in no
> replies.
> 
> On the 3550, the MAC address-table gets populated fine,
> occasionally I see
> an ARP entry for 172.40.1.1, but can't ping.
> 
> Any suggestions on what's going wrong?
> 

On a 3550 you may need a static arp for the ping to work, eg:

arp vrf network2 172.40.1.1 xxxx.xxxx.xxxx ARPA

If you debug arp you might see if this is the case. I think the switch has a problem that it sees the ARP request it sent out come back in on a different port.


> Is there a better way to acheieve what I'm trying to do?
> 

I'm not sure if you can achieve what you're wanting to on a 3550. We've always had to use 2x 3550 to break out a QinQ service (with crossover cable/s between them), instead of using one and looping it back onto itself.