I have a simple home router iptables setup. The router now runs Debian Lenny; the client runs Ubuntu. Since the Debian upgrade, the forwarding setup no longer works properly. The iptables router has two NICs; one connects to the cable modem, the other to an internal switch. Router is running Linux 2.6.26, iptables 1.4.2. The router box has no network issues with the Internet. I can ping, surf websites, etc.. The client box has no problems talking to the router. I can ssh to the router, mount NFS shares, etc.. Before the Lenny upgrade, the router box was forwarding Internet traffic from the client to the Internet without trouble. After the Lenny upgrade, I can no longer make any connection from the client to the Internet that transmits more than few bytes. I can ping from the client, do DNS lookups, and even get a short error message from an external website by telnetting from the client to port 80 on the external website and sending an invalid requst. If I send a *valid* request, however (e.g. GET /index.html HTTP/1.0), I get no response. The connection just times out. /proc/net/ip_conntrack shows all the relevant connections in CLOSE_WAIT or TIME_WAIT status. sysctl is properly configured: net.ipv4.conf.all.forwarding = 1 I have ip_masquerading enabled. I don't think this is a problem with the forwarding setup, since I am able to ping and make an initial HTTP connection to external hosts from the internal client. It's only when more than a few bytes are supposed to come back that it times out. Finally, just as an experiment, I tried reducing the MTU packet size on the client, but it made no difference. Nothing relevant appears in syslog or kernel logs. I tried logging packets in invalid state; no luck. Any suggestions on how to fix or further troubleshoot this? -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
