1) Comment the "GATEWAY=" line in the /etc/sysconfig/network file.
Let us first set some symbolical names. Let $IF1 be the name of the first interface and $IF2 the name of the second interface. Then let $IP1 be the IP address associated with $IF1 and $IP2 the IP address associated with $IF2. Next, let $P1 be the IP address of the gateway at Provider 1, and $P2 the IP address of the gateway at provider 2. Finally, let $P1_NET be the IP network $P1 is in, and $P2_NET the IP network $P2 is in.
2) Creates two additional routing tables, say T1 and T2. These are added in /etc/iproute2/rt_tables.
echo 1 T1 >> /etc/iproute2/rt_tables
echo 2 T2 >> /etc/iproute2/rt_tables
Eg :
================================
[root@test ~] # cat /etc/iproute2/rt_tables
#
# reserved values
#
255 local
254main
253default
0unspec
#
# local
#
#1inr . ruhep
1 T1
2 T2
================================
3) Then you set up routing in these tables as follows:
ip route add $P1_NET dev $IF1 src $IP1 table T1
ip route add default via $P1 table T1
ip route add $P2_NET dev $IF2 src $IP2 table T2
ip route add default via $P2 table T2
4)Next you set up the main routing table. Note the `src ' arguments, they make sure the right outgoing IP address is chosen.
Let us first set some symbolical names. Let $IF1 be the name of the first interface and $IF2 the name of the second interface. Then let $IP1 be the IP address associated with $IF1 and $IP2 the IP address associated with $IF2. Next, let $P1 be the IP address of the gateway at Provider 1, and $P2 the IP address of the gateway at provider 2. Finally, let $P1_NET be the IP network $P1 is in, and $P2_NET the IP network $P2 is in.
2) Creates two additional routing tables, say T1 and T2. These are added in /etc/iproute2/rt_tables.
================================
[root@test ~
#
# reserved values
#
255 local
254
253
0
#
# local
#
#1
1 T1
2 T2
================================
3) Then you set up routing in these tables as follows:
4)
5) Then, your preference for default route:
6) Next, you set up the routing rules. These actually choose what routing table to route with. You want to make sure that you route out a given interface if you already have the corresponding source address:
7) Put the above commands in the /etc/
Example:
########################
ip route add 210.61.156.0/24 dev eth0 src 210.61.156.253 table T1
ip route add default via 210.61.156.254 table T1
ip route add 59.125.26.0/24 dev eth1 src 59.125.26.34 table T2
ip route add default via 59.125.26.254 table T2
ip route add 210.61.156.0/24 dev eth0 src 210.61.156.253
ip route add 59.125.26.0/24 dev eth1 src 59.125.26.34
ip route add default via 210.61.156.254
ip rule add from 210.61.156.253 table T1
ip rule add from 59.125.26.34 table T2
#########################
8) Reboot the VM and check if eth0 and eth1 are responding to ping requests.
########################
#########################
8) Reboot the VM and check if eth0 and eth1 are responding to ping requests.
Reference:
