[c-nsp] Cisco 6500 VLAN Question

[Nick Hilliard]

On 23/01/2013 19:40, Chris Gotstein wrote:
> We use an appliance to control bandwidth and setup packages for our
> customers, so it needs to be in the location it's at so I can feed it
> multiple connections from different areas.  It wasn't as big of a deal when
> all our connections came through a single backhaul, but now we are adding
> additional fiber connections that all need to go through this one box.

I can understand why you might be tempted to do this from a business
convenience point of view, but from a network architecture point of view,
your design is not scalable and sooner or later it will break.

If you really want to design your network around this, QinQ will possibly
do the job, but you'll have to decapsulate the outer q tag in the shaper
box.  It's not hard to do - you just strip off a dot1q tag, but if your
packet shaping box doesn't support it, you're stuck.  Conversely you're not
going to be able to ship a whole pile of vlans out on one port and back in
on another port because the 6500 doesn't do local vlan significance, at
least on LAN cards (i.e. vlan X on port Y will be the same as vlan X on
port Z).

If I were in your socks, I'd make plans to push this component out of the
design and push the QoS policy management out to your network edge.  It
will scale much better than your current mechanism.

Nick