Ok!
So, I've been slowly deploying MPLS throughout my network and have run into some glitches that I thought I should bring to attention and ask some questions about.

Here's the scenario:
When I run MPLS between RouterBoards (actual Mikrotik products), it works just fine.
But, when I run MPLS between a RouterBoard and x86 hardware or between just x86 hardware, the following happens:
- I can no longer access the devices behind the "MPLS line" (where MPLS begins in my network) via Winbox
- Packets larger than 1492 bytes do not get through (hence stopping approx. 90% of all traffic) (MTU discovery doesn't fix this)

My conclusion:
On Mikrotik hardware, the L2MTU is large enough to handle MPLS, and it's adjustable. On non-mikrotik hardware, the L2MTU is not big enough nor adjustable.

I have read _all_ the documentation on MikroTik's implementation of MPLS and L2MTU I can find and the documentation supports my conclusion.

My questions:
- What brand and model of ethernet chip supports the L2MTU setting?
- Does anyone know of a Quad-Port PCI-express card featuring the chip mentioned above?
- Can I get a consensus on standardizing the ethernet hardware support list on the wiki? Namely, I would like to clean the list up and make columns for particular features supported, namely things like L2MTU, VLAN, Version tested, etc.
- Can I get some cooperation from Mikrotik to make their compatibility information more available? (I.E. If you have the results from hardware tests that you are keeping to yourself, please make it available)


It seems that Mikrotik is going the way of crowdsourcing their manuals, etc. But the only way for that to work is if we all can cooperate on how the information will be presented, standardized, etc. Can I get some thoughts on this?

Thanks guys,
Dust

bump

This might be of help?

http://wiki.mikrotik.com/wiki/MTU

Most mikrotik boards support at least mtu of 1522...X86 ethernet cards normally have an l2mtu of 1500