Hi all Something that seems simple here, but I cannot find anything wrong I have two machines here, A and B. A have eth0 and eth1, and a DSL connection (ppp0) with the modem connected to eth0. B have eth0. I have A.eth1 connected to B.eth0, and I'm trying to use A as a gateway for B. It works, from B I can reach anything I can do from A, with ping, tracereroute and resolve names, but I can't use other protocols like HTTP, FTP, IRC, and it seems to happen on a random basis. Sometimes it works, sometimes it waits for data until timeout... I tried to find a pattern on it but I couldn't. I tried to use LOG and netwatch on ppp0 and eth1 to debug it, there's no data coming from the remote on these cases. Someone suggested I should upgrade the kernel, so I'm using the latest version, 2.6.17.7 #4, but still doesn't work... Here's the ruleset I'm using on the gateway... pretty simple <code> #!/bin/bash echo 1 > /proc/sys/net/ipv4/ip_forward IPT="iptables --verbose" $IPT -F $IPT -t nat -F $IPT -P INPUT ACCEPT $IPT -P OUTPUT ACCEPT $IPT -P FORWARD ACCEPT $IPT -A INPUT -j ACCEPT -i lo $IPT -A INPUT -j ACCEPT -s 192.168.1.0/24 $IPT -A INPUT -i ppp0 -m state --state ESTABLISHED,RELATED -j ACCEPT $IPT -A INPUT -j ACCEPT -p tcp --dport 3306 $IPT -A INPUT -j ACCEPT -p tcp --dport 3690 $IPT -A INPUT -j ACCEPT -p tcp --dport 8000:8010 $IPT -A INPUT -j ACCEPT -p tcp --dport 8021 $IPT -A INPUT -j ACCEPT -p tcp --dport 8022 $IPT -A INPUT -j ACCEPT -p tcp --dport 8080 $IPT -A FORWARD -j ACCEPT -i ppp0 $IPT -A FORWARD -j ACCEPT -s 192.168.1.0/24 $IPT -A FORWARD -j DROP $IPT -t nat -A POSTROUTING -s 192.168.1.0/24 -o ppp0 -j MASQUERADE </code> And here's the modules I have loaded (lsmod | grep ip), in case something is missing and I haven't noticed: ipt_LOG 5440 0 ipt_MASQUERADE 2560 1 iptable_mangle 2240 0 iptable_nat 5636 1 ip_nat 12844 2 ipt_MASQUERADE,iptable_nat ip_conntrack 36564 4 ipt_MASQUERADE,xt_state,iptable_nat,ip_nat iptable_filter 2240 1 ip_tables 9944 3 iptable_mangle,iptable_nat,iptable_filter x_tables 9668 6 ipt_LOG,xt_tcpudp,ipt_MASQUERADE,xt_state,iptable_nat,ip_tables Since it seems something very weird, I'm asking for your help here. Any idea about what's wrong here ? Thanks... -- Pedro Werneck
