[f-nsp] Enabling Q-in-Q on RX

[Rob Lister]

Greetings,

I have a customer that would like us to enable a q-in-q trunk across a 
network of RX-8s, and the documentation seems a little vague in places.

If anyone has enabled this on RX / XMR platform, I would greatly 
appreciate any advice on what happens when it's enabled.

The documentation for RX suggests doing:

BigIron RX(config)# tag-type 9100 e3/1 to 3/2
BigIron RX(config)# aggregated-vlan

1. What is the interaction between the 'aggregated-vlan' command
   and the default-max-frame-size on RX? 
   
   Behaviour of the smaller (non-RX) switches:
   
  SW3(config)#default-mtu 1600
  Aggregated VLAN is in effect.10/100M ports will be set to default MTU 1530.

 SW3#show int ethe 3
 FastEthernet3 is down, line protocol is down
  ...
  MTU 1530 bytes, encapsulation ethernet
  ...

  ... After reload, however, it sets it back to 1600.

  The RX doesn't quite have the same options, however, but doesn't 
  suggest a frame limit for aggregated-vlan.

  So.. on an RX q-in-q port, what can the maximum MTU be? 
  What's the default "mini-jumbo" frame size?

RX:

SSH at RX-8(config)#agg?
  aggregated-vlan               Allow mini-jumbo frames to allow multiple 
                                vlan tags

FI4802:

SW3(config)#agg
  aggregated-vlan               support for larger Ethernet frame up to 1530
                                bytes


2. Changing tag-type on the RX.

   Documentation points out that it will change it for a port region,
   not just the ports involved.

   "Note that since ports 11 and 12 belong to the port region 1 – 12, 
    the 802.1Q tag actually applies to ports 1 – 12."

   It doesn't say what happens to the other ports, though.

   Does this mean that we cannot use the other ports not involved in the
   q-in-q configuration for normal (non q-n-q traffic?) What happens if
   it receives normal untagged frames?

   The documentation is also unclear about port regions, as it then 
   suggests, under "enabling 802.1q tag-type translation":

   "Note that since ports 11 and 12 belong to the port region 9 – 16, the 
   802.1q tag-type actually applies to ports 9 – 16."

   So which is it? A port region of 8 or 12 ports? I am thinking it's 12,
   as there is more mention of that.


If anyone has set this up I would appreciate any pointers/hints!


thanks,


Rob