I had this problem and solved out with putting default gw (Mikrotik) for all nongaming computers and redirection to proxy – that was one modem on the LAN. I had redirected traffic for browsing on all gaming computers through the same modem (Internet options->Connections->LAN settings->Proxy server I’d put Mikrotik address there).
Then I’d put second gw for gaming computers here:Network Connections->Local area connection->Properties->TCPIP->Properties->Advanced…-IP settings->Default gateways->Add…
But this configuration is not good because problems with traffic shaping on second gw and with p2p traffic still remains.
So maybe now you will understand how frustrated I am in my trials to get through with MikroTik with this configuration, because if it would work you would not need to ask or even to search another solution you do now.
Just read carefully what way i coming from in topic http://forum.mikrotik.com/t/2-isp-providers-wan-one-lan-with-mikrotik-in-game-centre/4464/1
and you will see MikroTik has perfect solution, but how to make it alive.
For Gods sake, what are you talking about?
I’m not showing you MikroTik configuration here. I’m saying again: If you will configure Mikrotik as proxy server, then browsing traffic can go trough the one modem (through Mikrotik at first, of course), but all the rest traffic can go by default gw (another modem), which you can set manualy on every computer.
How can you say that this is not working? Only, if you don’t have Mikrotik as proxy, I can agree…