redhat 7 policy based routing fails
by jorism from LinuxQuestions.org on (#517CS)
On a redhat 7 system we want to be able to choose the source interface for outgoing traffic based on which interface the traffic came in. We tried using ip rule and ip route. Even the most simple rule like this does not work (tcp only shows incoming SYN packets).
This is the config:
ip rule
0: from all lookup local
32761: from all iif eth0 lookup outgoing
32766: from all lookup main
32767: from all lookup default
ip route show table outgoing
default via 10.82.191.33 dev eth0
For incoming packets from a certain host, let's say 168.63.129.16, in only see incoming SYN packets. I get the impression that the ip rule is not triggered or working. Difficult to debug!
Help (please) ! Help?
The available interfaces;
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:0d:3a:38:fc:c2 brd ff:ff:ff:ff:ff:ff
inet 10.82.191.37/28 brd 10.82.191.47 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20d:3aff:fe38:fcc2/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:0d:3a:aa:61:07 brd ff:ff:ff:ff:ff:ff
inet 10.82.191.4/27 brd 10.82.191.31 scope global noprefixroute eth1
valid_lft forever preferred_lft forever
inet 10.82.191.7/27 brd 10.82.191.31 scope global secondary noprefixroute eth1:2
valid_lft forever preferred_lft forever
inet 10.82.191.5/27 brd 10.82.191.31 scope global secondary noprefixroute eth1:0
valid_lft forever preferred_lft forever
inet 10.82.191.6/27 brd 10.82.191.31 scope global secondary noprefixroute eth1:1
valid_lft forever preferred_lft forever
inet6 fe80::20d:3aff:feaa:6107/64 scope link
valid_lft forever preferred_lft forever
This is the config:
ip rule
0: from all lookup local
32761: from all iif eth0 lookup outgoing
32766: from all lookup main
32767: from all lookup default
ip route show table outgoing
default via 10.82.191.33 dev eth0
For incoming packets from a certain host, let's say 168.63.129.16, in only see incoming SYN packets. I get the impression that the ip rule is not triggered or working. Difficult to debug!
Help (please) ! Help?
The available interfaces;
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:0d:3a:38:fc:c2 brd ff:ff:ff:ff:ff:ff
inet 10.82.191.37/28 brd 10.82.191.47 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20d:3aff:fe38:fcc2/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:0d:3a:aa:61:07 brd ff:ff:ff:ff:ff:ff
inet 10.82.191.4/27 brd 10.82.191.31 scope global noprefixroute eth1
valid_lft forever preferred_lft forever
inet 10.82.191.7/27 brd 10.82.191.31 scope global secondary noprefixroute eth1:2
valid_lft forever preferred_lft forever
inet 10.82.191.5/27 brd 10.82.191.31 scope global secondary noprefixroute eth1:0
valid_lft forever preferred_lft forever
inet 10.82.191.6/27 brd 10.82.191.31 scope global secondary noprefixroute eth1:1
valid_lft forever preferred_lft forever
inet6 fe80::20d:3aff:feaa:6107/64 scope link
valid_lft forever preferred_lft forever