Thanks for all your replies and explanations. Sure lowering mtu below 1500 bytes for all hosts or using jumbo frames would be the right solution especially for corporate network.
But we probably have to stick to 1500 bytes for one reason: that FreeBSD-based router configuration I mentioned is for segments where we use seperate vlan for each client connection (we're an ISP): it seems that using anything else instead of 1500 for clients will require too much tech support efforts. Since double-tagged frames will be transmitted only by one ethernet link per segment (the link between upper level switch with QinQ and FreeBSD router) then maybe it's acceptable to allow a little deviation from the standard as long as we remember the implications. Thanks for the help Ivan _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"