Channel balancing in linux?

Question

linux

Task: we have ubuntu server 10.04, and two internet channels. Channel A is fast but with gray ip, channel B is slow but with white ip. It is necessary that all outgoing connections go through channel A, but if there is an incoming connection from channel B, then it is necessary that the response goes to channel B. Is it possible to implement this?

Answer 1

It is necessary to make 2 separate routing tables for each channel with different default routes. Next, using iptables, we mark
the necessary packets depending on your wishes and send them to one or another routing table using ip route . dport 53 -j MARK --set-mark 2 # turn all packets with mark 2 into germany routing table ip rule add fwmark 2 table germany

Answer 2

IP1=`/sbin/ifconfig $IF1 | grep “inet addr:” | cut ­d ” ” ­f 12 | cut ­d “:” ­f 2`
P1=`/sbin/ifconfig $IF1 | grep “inet addr:” | cut ­d ” ” ­f 14 | cut ­d “:” ­f 2`
I didn’t understand something, where did 12 or 14 fields come from