Why is iptables forwarding between two interfaces not working?

Why is iptables forwarding between two interfaces not working?

Here’s what I’ve tried so far with iptables but it’s not working: I’d appreciate any help. First, to enable hosts connecting on your private interface to go out to the internet, you don’t need bridging the interfaces, you need to route packets coming in on one interface, to the other one, where they go out to the wild.

What causes a packet to not be forwarded?

L2 loops in a switched network with redundant links cause frequent changes to the MAC address table on the switches used for forwarding frames. This results in the devices appearing to be connected through different ports at different times and forwarding frames out of the incorrect port.

How to forward packets from one interface to the other?

I’d appreciate any help. First, to enable hosts connecting on your private interface to go out to the internet, you don’t need bridging the interfaces, you need to route packets coming in on one interface, to the other one, where they go out to the wild. That should do it. Thanks for contributing an answer to Server Fault!

Why does my Cisco device have an incomplete IP address?

In certain situations, a Cisco device contains incomplete entries in the ARP table which will have the IP address, but the MAC address is marked as incomplete. This situation is due to no ARP reply being received by the device for the ARP request that was sent out.

How to route traffic between interfaces on same router-Cisco?

No ACL’s. I thought I only needed to make the routing table. I can get out from the inside network 2 to the internet. However, hosts on either network cannot access each other. I know I am missing something but not sure what. Can someone please advise what I am doing wrong? 07-02-2013 02:00 PM 07-02-2013 02:00 PM

How to use split tunneling in a VPN?

With most VPN services that offer split tunneling you can also specify a list of routes to push to the client — these are the subnets that will be accessible across the tunnel. Anything not in these routes will follow the regular path at the client’s location – which would mean their ISP.

Why do I need to enable traffic to both interfaces?

I want to be able to enable traffic to both interfaces so hosts on each network can communicate with each other and still go out to wan on the 10.10.10.100 interface. I do not have vlans configured, just interfaces.

How does ebtables interact with iptables in Linux?

This document describes how iptables and ebtables filtering tables interact on a Linux-based bridge. Getting a bridging firewall on a 2.4.x kernel consists of patching the kernel source code. The 2.6 kernel contains the ebtables and br-nf code, so it doesn’t have to be patched.

Can a bridge be contacted from any interface?

The bridge has an IP address, and the machine can be contacted on that IP address from either interface. However, I don’t know what to configure to get traffic flowing across the bridge, between the interfaces.

Do you need to set ip forward to 1 on a bridge?

Ideally only traffic between the interfaces should be forwarded, so that the machine cannot be used as a bounce point within the network. You shouldn’t need to set the ip_forward = 1 unless the interface is acting as a NAT for the other devices, which shouldn’t be the case if you’ve set them up as a bridge.