Dear all,
is anybody having success in using Q in Q (which means VLANS over VLANS) without getting stuck in MTU Problems?
Did anybody succeed in transfering Q in Q in any form over an 'Master' EOIP Tunnel ?

My Test with two directly connected RB1000 with ROS 3.16 devices failed with following Problems:
- All MTU Values kept default with 1500, a vlan created on both boxes, each with an ip adress as transfernet, below this vlan a secondary vlan again with an additional transfernet - ping works fine on both, but in the secondary vlan only with frames of maximum size 1496

- All MTU Parrent Mtus (Ethernet & VLAN) increased to 1504, a vlan created on both boxes, each with an ip adress as transfernet, below this vlan (MTU 1504) a secondary vlan (MTU 1500) again with an additional transfernet - ping works fine on both, but in the secondary vlan again only with frames of maximum size 1496

- Additional i tried to establish VLAN over VLAN over an EOIP Tunnel, to prevent the problem in creating hundreds of Tunnels for transfering VLAN Traffic from one remote to the other site and also to have better redundancy. But my test was absolutely without success. The secondary VLAN didn't reach the secondary VLAN on the remote side. With the primary VLAN everything was fine.

Please share your Q in Q experience with me...

Regards from Austria,
Wolfgang

QinQ is working ok, and with 3.15 we are able to set the MTU on our card 00:19:5B:FE:83:XX to be 1514. In this case we bridge the inner vlan to an EoIP tunnel for transport across our network. I have not tried to bridge a VLAN with multiple inner VLANs to an EoIP tunnel though.

You must configure the outer vlan on the RB's interfaces and bridge between the vlan interfaces. Make sure you do not bridge the parent interfaces (the physical ones). It worked for me on 3.13 on RB411 using that specific method.
I think the driver/NIC does not open for larger than vlan packets (and Q-in-Q packets are 4 bytes larger than regular vlan packets) unless you do that specific method.

You must configure the outer vlan on the RB's interfaces and bridge between the vlan interfaces. Make sure you do not bridge the parent interfaces (the physical ones). It worked for me on 3.13 on RB411 using that specific method.
I think the driver/NIC does not open for larger than vlan packets (and Q-in-Q packets are 4 bytes larger than regular vlan packets) unless you do that specific method.

mmc,

now with 802.1ad (Q in Q) support in RouterOS v3.23 you can do that ! Try!