After following the following article (with some tweaks for testing purposes) I still can't get traffic to route across multiple DSL lines:
http://linux-ip.net/html/adv-multi-internet.html
Here is my setup. As you can see I've changed the iptables rule from "if destination is port 80/443" to "if destination is ip 67.71.152.161" because I currently can only test from one host, the gateway, so the routing decision has to be made on the basis of destination and not client IP.
The gateway is connected to a hub that has two WAN gateways, 192.168.
0.1 and 192.168.
1.1 which are Cisco routers to two different ISPs (Telus and Sprint).
The NIC setup
Code:
[root@wifi etc]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0A:E6:77:50:C0
inet addr:192.168.1.200 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::20a:e6ff:fe77:50c0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:18854 errors:0 dropped:0 overruns:0 frame:0
TX packets:5668 errors:0 dropped:0 overruns:0 carrier:0
collisions:7 txqueuelen:1000
RX bytes:1793892 (1.7 Mb) TX bytes:778809 (760.5 Kb)
Interrupt:11 Base address:0xdc00
eth0:1 Link encap:Ethernet HWaddr 00:0A:E6:77:50:C0
inet addr:192.168.0.200 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:11 Base address:0xdc00
The iptables rules - SNAT masked, unshown rules are empty
Code:
[root@wifi etc]# iptables -t mangle -L -v
Chain PREROUTING (policy ACCEPT 1175 packets, 94882 bytes)
pkts bytes target prot opt in out source destination
0 0 MARK all -- any any anywhere 67.71.152.161 MARK set 0x4
[root@wifi etc]# iptables -t nat -L -v
Chain PREROUTING (policy ACCEPT 32 packets, 3542 bytes)
pkts bytes target prot opt in out source destination
Chain POSTROUTING (policy ACCEPT 107 packets, 4298 bytes)
pkts bytes target prot opt in out source destination
0 0 SNAT all -- any eth4 anywhere anywhere to:149.99.555.555
The Routing Tables - unshown rules are empty
Code:
[root@wifi etc]# ip route show table main
192.168.1.0/24 dev eth0 scope link
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.200
169.254.0.0/16 dev eth0 scope link
127.0.0.0/8 dev lo scope link
default via 192.168.1.1 dev eth0
[root@wifi etc]# ip route show table 4
192.168.1.0/24 dev eth0 scope link
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.200
169.254.0.0/16 dev eth0 scope link
127.0.0.0/8 dev lo scope link
default via 192.168.0.1 dev eth0
[root@wifi etc]# ip rule show
0: from all lookup local
32765: from all fwmark 0x4 lookup 4
32766: from all lookup main
32767: from all lookup default
Any and all comments are welcome.
EDIT: I originally asked if it could be failing because of incorrect SNATting but I've since fixed that, so now the SNAT properly mangles the packet to appear from the correct ISP gateway.
