Possible reasons for packet loss?

Discussion in 'Computing and Networks' started by alexhutnik, Oct 1, 2008.

  1. alexhutnik

    Thread Starter New Member

    Oct 1, 2008
    I have three networks at home, connected together on a single linux box (router, DHCP, DNS):

    eth0: wired,, where the router resides at
    eth1: wireless,, wireless router has address
    eth2: cable modem, 76.xxx.xxx.xxx

    When I ping a host on the wired LAN (say, 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 * U 0 0 0 eth0 * U 0 0 0 eth1
    76.xxx.xxx.0 * U 0 0 0 eth2
    link-local * U 1000 0 0 eth1
    default cpe-76-xxx-xxx- UG 100 0 0 eth2

    Any ideas?
    Last edited: Oct 1, 2008
  2. AlexR

    Well-Known Member

    Jan 16, 2008
    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.
  3. alexhutnik

    Thread Starter New Member

    Oct 1, 2008
    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.