On Tuesday 29 June 2004 2:02 pm, Mike O wrote: > Im trying to track down a problem Im having with iptables. For some reason > the internal machines cannot reach the internet until I ping them from the > iptables box. I check the conntrack tables and there still valid entries in > there for that machine. if I reboot it works for about 5 minutes then > stops. I tried upgrading the kernel to 2.4.26 and iptables 1.2.11 and the > same problem happens. Any ideas? this was working fine for over 6 months > then just starts doing this. Sounds like the client machines can't do ARP resolution for the IP address of the gateway. I would suspect: 1. The NIC on the firewall. 2. The switch on your LAN. Wait until one of the clients cannot get to the Internet, then examine its ARP cache ("arp -an" on Linux, not sure about other O/Ss), and see if it has a complete entry for the IP address of the firewall's internal interface. Then do your ping and repeat the ARP check. Regards, Antony. -- "The future is already here. It's just not evenly distributed yet." - William Gibson Please reply to the list; please don't CC me.