I have total 4 Interfaces on my VM where enp0s3 is the primary Interface and others are the secondary Interfaces
ip a output
[root@vm]# ip a
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: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 xdp/id:1 qdisc sfq state UP group default qlen 1000
link/ether 02:00:17:01:c1:5d brd ff:ff:ff:ff:ff:ff
inet 100.10.10.100/24 brd 100.10.10.255 scope global dynamic enp0s3
valid_lft 81440sec preferred_lft 81440sec
inet6 fe80::17ff:fe01:c15d/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UP group default qlen 1000
link/ether 02:00:17:01:6c:5d brd ff:ff:ff:ff:ff:ff
inet 100.10.10.101/24 scope global enp1s0
valid_lft forever preferred_lft forever
4: enp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UP group default qlen 1000
link/ether 02:00:17:00:a2:f3 brd ff:ff:ff:ff:ff:ff
inet 100.10.10.102/24 scope global enp2s0
valid_lft forever preferred_lft forever
5: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UP group default qlen 1000
link/ether 02:00:17:01:a7:4e brd ff:ff:ff:ff:ff:ff
inet 100.10.10.103/24 scope global enp3s0
valid_lft forever preferred_lft forever
I am redirecting incoming traffic from ports 9100, 9101, 9102, 9103 to some specific ips using the rules
iptables -t nat -A PREROUTING -p udp --dport 9100 -j DNAT --to 1.1.1.1:9100
iptables -t nat -A POSTROUTING -p udp -d 1.1.1.1 --dport 9100 -j MASQUERADE
iptables -t nat -A PREROUTING -p udp --dport 9101 -j DNAT --to 2.2.2.2:9101
iptables -t nat -A POSTROUTING -p udp -d 2.2.2.2 --dport 9101 -j MASQUERADE
iptables -t nat -A PREROUTING -p udp --dport 9102 -j DNAT --to 3.3.3.3:9102
iptables -t nat -A POSTROUTING -p udp -d 3.3.3.3 --dport 9102 -j MASQUERADE
iptables -t nat -A PREROUTING -p udp --dport 9103 -j DNAT --to 4.4.4.4:9103
iptables -t nat -A POSTROUTING -p udp -d 4.4.4.4 --dport 9103 -j MASQUERADE
iptables -t nat -A PREROUTING -p udp --dport 1245 -j DNAT --to 5.5.5.5:1245
iptables -t nat -A POSTROUTING -p udp -d 5.5.5.5 --dport 1245 -j MASQUERADE
I wanted 1.1.1.1 & 2.2.2.2 shall pass traffic from enp2s0 and 3.3.3.3 & 4.4.4.4 shall pass traffic from enp3s0
IP 5.5.5.5 it wanted the traffic to pass from enp1s0 so I used a commad
ip route add 100.10.10.0/24 dev enp1s0 scope link metric 1000 table
main ip route add 5.5.5.5/32 via 100.10.10.1 dev enp1s0 table main
It Worked
But when I use the same rules for other interfaces It doesn’t work
I used these rules from below
ip route add 100.10.10.0/24 dev enp2s0 scope link metric 1000 table main
ip route add 1.1.1.1/32 via 100.10.10.1 dev enp2s0 table main
ip route add 100.10.10.0/24 dev enp2s0 scope link metric 1000 table main
ip route add 2.2.2.2/32 via 100.10.10.1 dev enp2s0 table main
ip route add 100.10.10.0/24 dev enp3s0 scope link metric 1000 table main
ip route add 3.3.3.3/32 via 100.10.10.1 dev enp3s0 table main
ip route add 100.10.10.0/24 dev enp3s0 scope link metric 1000 table main
ip route add 4.4.4.4/32 via 100.10.10.1 dev enp3s0 table main
Can someone please help me in this case. I am not good at routing. Thanks in Advance
