KEYWORDS: Linux, Routing, two interfaces with public ip.


OK, here is scenario:

You have same machine with three ethernet cards. eth1 is 
private network, eth0 and eth2 are interfaces with public ip.
(195.252.127.2 and 195.250.117.242 in my case). If you
put default gateway on 195.252.127.1 195.250.117.242 won't be 
visible since packages traveling from 195.250.117.242
can't travel through 195.252.127.2 (and they will be routed
through 195.252.127.1). Here is solution:

/sbin/ip rule add to 195.250.117.242 table 101
/sbin/ip route add 0/0 via 195.250.117.241 dev eth2 table 101
/sbin/ip rule add from  195.250.117.242 table 102
/sbin/ip route add 0/0 via 195.250.117.241 dev eth2 table 102

You need iproute2 and routing in your kernel.. etc.

16.12.2003.
gg.

  (public)               (public)
195.252.127.2          195.250.117.242
---[eth0]---+        +----[eth2]----
            |        |
          [linux router]    
                |
              [eth1]
                |
          (private network)

two real ip on different ISP.