I have a Slackware box that I've set up as a router for my home network. It does that and zoneminder and that's pretty much it. It's worked fine for a few years doing this until today.
Today the power went out and the UPS could only keep this machine up for about 45 mins before it ran out of power. When the power came back up the I turned on the slackware box and it booted normally. Everything started up fine but one problem.
I have 4 other machines in the house that connect to the internet. None of them will pull up a web page. They will however ping and resolve anything on the outside world without a problem. My slackware box will load websites without a problem but anything on the internal network will not bring up a web page even though all of it can talk to the outside world. I know the problem is with this slackware box routing the web pages because my laptop and phone will both connect to my neighbor's internet and work fine.
It's like it's trying to work, I can ping websites so I know the machines on my internal network can not only see the outside world they can resolve domain names. It just won't let anything on the internal network fetch web pages.
I'm running slackware 13 and it's you basic dnsmasq setup with two lan cards. eth0 going to the cable modem and eth1 going to my switch.
I don't understand what could have changed. I suspect it's iptables that's changed some how. here's my output for iptables.
Chain INPUT (policy DROP 39 packets, 1686 bytes)
pkts bytes target prot opt in out source destination
39931 77M ACCEPT all -- lo any anywhere anywhere
807K 38M bad_packets all -- any any anywhere anywhere
94 2632 DROP all -- any any anywhere ALL-SYSTEMS.MCAST.NET
790K 32M ACCEPT all -- eth1 any 192.168.1.0/24 anywhere
0 0 ACCEPT all -- eth1 any anywhere 192.168.1.255
12796 4925K ACCEPT all -- eth0 any anywhere anywhere state RELATED,ESTABLISHED
44 1896 tcp_inbound tcp -- eth0 any anywhere anywhere
4137 1337K udp_inbound udp -- eth0 any anywhere anywhere
0 0 icmp_packets icmp -- eth0 any anywhere anywhere
0 0 DROP all -- any any anywhere anywhere PKTTYPE = broadcast
39 1686 LOG all -- any any anywhere anywhere limit: avg 3/min burst 3 LOG level warning prefix `INPUT packet died: '
Chain FORWARD (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
3930 419K bad_packets all -- any any anywhere anywhere
425 46970 tcp_outbound tcp -- eth1 any anywhere anywhere
1682 124K udp_outbound udp -- eth1 any anywhere anywhere
4 240 ACCEPT all -- eth1 any anywhere anywhere
1788 246K ACCEPT all -- eth0 any anywhere anywhere state RELATED,ESTABLISHED
0 0 LOG all -- any any anywhere anywhere limit: avg 3/min burst 3 LOG level warning prefix `FORWARD packet died: '
Chain OUTPUT (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 DROP icmp -- any any anywhere anywhere state INVALID
173 15642 ACCEPT all -- any any localhost anywhere
39758 77M ACCEPT all -- any lo anywhere anywhere
214 33523 ACCEPT all -- any any 192.168.1.1 anywhere
585K 1763M ACCEPT all -- any eth1 anywhere anywhere
10988 1544K ACCEPT all -- any eth0 anywhere anywhere
0 0 LOG all -- any any anywhere anywhere limit: avg 3/min burst 3 LOG level warning prefix `OUTPUT packet died: '
Chain bad_packets (2 references)
pkts bytes target prot opt in out source destination
0 0 LOG all -- eth0 any 192.168.1.0/24 anywhere LOG level warning prefix `Illegal source: '
0 0 DROP all -- eth0 any 192.168.1.0/24 anywhere
32 1280 LOG all -- any any anywhere anywhere state INVALID LOG level warning prefix `Invalid packet: '
32 1280 DROP all -- any any anywhere anywhere state INVALID
802K 37M bad_tcp_packets tcp -- any any anywhere anywhere
811K 39M RETURN all -- any any anywhere anywhere
Chain bad_tcp_packets (1 references)
pkts bytes target prot opt in out source destination
790K 32M RETURN tcp -- eth1 any anywhere anywhere
0 0 LOG tcp -- any any anywhere anywhere tcp flags:!FIN,SYN,RST,ACK/SYN state NEW LOG level warning prefix `New not syn: '
0 0 DROP tcp -- any any anywhere anywhere tcp flags:!FIN,SYN,RST,ACK/SYN state NEW
0 0 LOG tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/NONE LOG level warning prefix `Stealth scan: '
0 0 DROP tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/NONE
0 0 LOG tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,SYN,RST,PSH,ACK,URG LOG level warning prefix `Stealth scan: '
0 0 DROP tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,SYN,RST,PSH,ACK,URG
0 0 LOG tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,PSH,URG LOG level warning prefix `Stealth scan: '
0 0 DROP tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,PSH,URG
0 0 LOG tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,SYN,RST,ACK,URG LOG level warning prefix `Stealth scan: '
0 0 DROP tcp -- any any anywhere anywhere tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,SYN,RST,ACK,URG
0 0 LOG tcp -- any any anywhere anywhere tcp flags:SYN,RST/SYN,RST LOG level warning prefix `Stealth scan: '
0 0 DROP tcp -- any any anywhere anywhere tcp flags:SYN,RST/SYN,RST
0 0 LOG tcp -- any any anywhere anywhere tcp flags:FIN,SYN/FIN,SYN LOG level warning prefix `Stealth scan: '
0 0 DROP tcp -- any any anywhere anywhere tcp flags:FIN,SYN/FIN,SYN
12101 4778K RETURN tcp -- any any anywhere anywhere
Chain icmp_packets (1 references)
pkts bytes target prot opt in out source destination
0 0 LOG icmp -f any any anywhere anywhere LOG level warning prefix `ICMP Fragment: '
0 0 DROP icmp -f any any anywhere anywhere
0 0 DROP icmp -- any any anywhere anywhere icmp echo-request
0 0 ACCEPT icmp -- any any anywhere anywhere icmp time-exceeded
0 0 RETURN icmp -- any any anywhere anywhere
Chain tcp_inbound (1 references)
pkts bytes target prot opt in out source destination
0 0 REJECT tcp -- any any anywhere anywhere tcp dpt:auth reject-with icmp-port-unreachable
8 432 ACCEPT tcp -- any any anywhere anywhere tcp dpt:http
3 144 ACCEPT tcp -- any any anywhere anywhere tcp dpt:smtp
0 0 ACCEPT tcp -- any any anywhere anywhere tcp dpt:pop3
0 0 ACCEPT tcp -- any any anywhere anywhere tcp dpt:imap
0 0 ACCEPT tcp -- any any anywhere anywhere tcp dpt:ssh
0 0 ACCEPT tcp -- any any anywhere anywhere tcp dpts:commplex-main:5100
0 0 ACCEPT tcp -- any any anywhere anywhere tcp dpts:6891:6900
0 0 ACCEPT tcp -- any any anywhere anywhere tcp dpt:auth
33 1320 RETURN tcp -- any any anywhere anywhere
Chain tcp_outbound (1 references)
pkts bytes target prot opt in out source destination
425 46970 ACCEPT tcp -- any any anywhere anywhere
Chain udp_inbound (1 references)
pkts bytes target prot opt in out source destination
32 3000 DROP udp -- any any anywhere anywhere udp dpt:netbios-ns
33 7701 DROP udp -- any any anywhere anywhere udp dpt:netbios-dgm
0 0 REJECT udp -- any any anywhere anywhere udp dpt:auth reject-with icmp-port-unreachable
0 0 ACCEPT udp -- any any anywhere anywhere udp dpt:domain
4066 1326K ACCEPT udp -- any any anywhere anywhere udp spt:bootps dpt:bootpc
6 366 RETURN udp -- any any anywhere anywhere
Chain udp_outbound (1 references)
pkts bytes target prot opt in out source destination
1682 124K ACCEPT udp -- any any anywhere anywhere