Home / server / Questions / 496731
In Process
GetFree
Asked: 2013-04-06 19:29:39 +0800 CST

How to set which IP to use for a HTTP request?

  • 772

This is probably a silly question.
I'm doing some http requests using wget from the command line, and I want those connections to be made through one specific IP of the 4 IPs my server has.
Those http requests go to one specific range of IPs so I only want those to be routed differently.
The 4 interfaces in my server are eth0, eth0:0, eth0:1, eth0:2.

I tried with the following command:
route add -net 192.164.10.0/24 dev eth0:0

But when I see the routing table it says:

Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
192.164.10.0    0.0.0.0         255.255.255.0   U         0 0          0 eth0

The interface is set to eth0 not eth0:0 as my command says.

What am I doing wrong?

linux

3 Answers

  1. wget --bind-address=192.0.2.116 http://file from man wget

    • 9

  2. If it's not wget, then there's this nifty little wrapper that you use LD_PRELOAD to insert before you run any command.

    You can use that to specifically bind, say, a browser to a VLAN interface (speaking from experience).

    • 3

  3. You could try to setup PBR (policy base routing) if you need more flexible routing (instead of --bind-address)

    IP1='xxx.xxx.xxx.62'
IF1='eth0'
GW1='xxx.xxx.xxx.61'
P1_NET='xxx.xxx.xxx.60/30'

IP2='yyy.yyy.yyy.10'
IF2='eth0:0'
GW2='yyy.yyy.yyy.9'
P2_NET='yyy.yyy.yyy.8/30'

IP3='zzz.zzz.zzz.239'
IF3='eth0:1'
GW3='zzz.zzz.zzz.254'
P3_NET='zzz.zzz.zzz.0/24'

/sbin/ip route add $P1_NET dev $IF1 src $IP1 table ISP1
/sbin/ip route add default via $GW1 table ISP1

/sbin/ip route add $P2_NET dev $IF2 src $IP2 table ISP2
/sbin/ip route add default via $GW2 table ISP2

/sbin/ip route add $P3_NET dev $IF3 src $IP3 table ISP3
/sbin/ip route add default via $GW3 table ISP3

/sbin/ip rule add from $IP1 table ISP1
/sbin/ip rule add from $IP2 table ISP2
/sbin/ip rule add from $IP3 table ISP3

/sbin/ip ru add fwmark 1 lookup ISP1 prio 100
/sbin/ip ru add fwmark 2 lookup ISP2 prio 200
/sbin/ip ru add fwmark 3 lookup ISP3 prio 300

/sbin/ip route add default via $GW1
/sbin/ip route flush cache

    And then use something like following

    iptables -t mangle -I OUTPUT -p tcp --dport 80 -j MARK --set-mark 1
    • 0