[c-nsp] l2protocol tunneling & 4500

[Garry]

Here's another one I encountered in our lab ... maybe it's something I
misunderstood, looking for some enlightenment ...

OK, core setup consists of two 4507 SupV-10GE, connected through the
TenG interfaces in a REP ring. Works fine so far.
Connected to those two switches (let's say c1 & c2) are four ME3400
switches, all of which going through their GigE ports as a 2G
etherchannel (with LACP). Ports are configured as trunks. The other
ports on the ME3400 will be used for a MAN application, interconnecting
customer sites via QinQ.

Now, network functions are fine so far.

I thought it might be an added value to the customers and added
functionality if the 4500's would tunnel stuff like the STP packets, so
I enabled l2protocol tunneling for STP, VTP and CDP (the latter mostly
for proof of concept).

This seemed to work fine, as now the CDP adjacencies for the ME's were
the other ME's and not the 4500 anymore (though every neighbor appeared
4 times, two port for both port each).

But then I noticed that one of the switches had both its uplink port
disabled. shut/no shut resulted in them being re-disabled due to
"misconfigured channels". As I couldn't find any difference (or fault)
in the switch's configuration, I rebooted it, which resulted in both
uplinks being active again - only to see the uplink ports on yet another
switch going down, with the same error message. Rebooting THAT switch
yet again led to a stable network, with all ME switches being up and
running fine. cdp neighbors were fine, communication between all
switches were also fine. Until I decided to reboot another of the ME
switches - when it came back up, the uplink ports of the second switch
went down again.

So, what am I missing here?

Tnx, garry