Hello, is it managable to load balance internet traffic on two cable modems but all traffic is comming from one local IP and that is SQUID proxy server.
Im sorry I forgot to write, I have tho cable modems, but they get IPs from the same subnet so I have same gateway adress.
Nothing? 
Search the forums for “+PCC +proxy”. There are several threads discussing this. Since you have the same gateway on both connections you’ll have to use interface notation for route gateways: 1.1.1.1%ether1. Though I’m not entirely clear on whether that works at all with broadcast interfaces. If it doesn’t you can’t balance the proxy traffic until you get two circuits on different subnets.
Unless you mean an external to the router (and thus non-local) proxy server, in which case the PCC wiki quite simply applies - but with the same interface route caveat.
Hi, it cannot be done, so I double natted one of modems. Now it is fine with tutorial from wiki.