Linux IP forwarding question
I have a linux machine with 3 NIC cards on it.
I want to be able to forward packets from eth3 to eth2 . I have ip forwarding enabled in the /sys/net/ipv4/ip_forward file. IP address of eth2 : 1.1.1.1 IP address of eth3 : 2.2.2.2 I set up the routing table . I have ethereal listening on eth1 . I used a traffic generator to send pkt to eth2. But I dont see the pkt on eth1. What am I missing? |
what happened to eth0???
|
I am not using eth0 at all - I just need forwarding between eth1 and eth2.
|
This is what I do to enable forwarding, I have 2 NICs, eth0 and eth1, and I forward packets back and forth between them (I'm running Fedora, don't know if it matters):
1. Modify in /etc/sysctl.conf: net.ipv4.ip_forward = 0 to net.ipv4.ip_forward = 1 2. Create /etc/sysconfig/network-scripts/ifcfg-ethX: The important entry is: GATEWAYDEV=ethY Create /etc/sysconfig/network-scripts/ifcfg-ethY: The important entry is: GATEWAYDEV=ethX - where X and Y are the 2 interfaces you're forwarding packets between 3. Add to /etc/sysconfig/network: FORWARD_IPV4 = yes 4. Modify /proc/sys/net/ipv4/ip_forward: Change to 1 |
I will try this out. I can't connect the 2 interfaces using crossover (since I need to pump traffic into eth2 from a traffic generator). So can I connect the 2 interfaces through a switch?
And, I need to set up the routing table too, right? |
All times are GMT -5. The time now is 03:07 PM. |