I have three networks at home, connected together on a single linux box (router, DHCP, DNS):

eth0: wired, 192.168.0.0/24, where the router resides at 192.168.0.1
eth1: wireless, 192.168.10.0/24, wireless router has address 192.168.10.3
eth2: cable modem, 76.xxx.xxx.xxx

When I ping a host on the wired LAN (say, 192.168.0.12) from the wireless LAN (by plugging in to the wireless router with an ethernet cable), I get about 50% packet loss.

Here is my iptables config:

-A FORWARD -i eth0 -j ACCEPT
-A FORWARD -i eth1 -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j ACCEPT
-A INPUT -i eth1 -j ACCEPT

And my route table:
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
192.168.10.0 * 255.255.255.0 U 0 0 0 eth1
76.xxx.xxx.0 * 255.255.224.0 U 0 0 0 eth2
link-local * 255.255.0.0 U 1000 0 0 eth1
default cpe-76-xxx-xxx- 0.0.0.0 UG 100 0 0 eth2

Any ideas?

 

The fact that you get a 50% packet loss point to a routing problem rather than a cable/NIC fault.

The first thing I would do is check that none of your hosts is running RIP, in fact turn off all RIP on your network. You have only one router on your network so its pointless running a routing protocol and hosts running routing protocols invariability cause routing loops and packet loss.

 

Thanks for the reply.

I looked through the settings pages and there doesn't seem to be an option to do anything with RIP (I have a Netgear WGR614v9). Unfortunately, I don't have another hub or switch handy. Then, I would just remove from my config and be able to confirm whether or not the router is an issue.

I'll also fire up wireshark and see if there are too many RIP-type packets.