I just had to relocate my debian sarge server to a new location. When I shut the machine off, everything worked great. When I turned it on with a new isp, I'm having trouble with incomming traffic on port 80.
I have a highly intensive iptables firewall. Rules are broken down so that only incoming/outgoing traffic is allowed to specific sites. http://ftp.egr.msu.edu/ is one such site. When iptables is started and the firewall is up, I can initiate a connection to http://ftp.egr.msu.edu/ via the command line (wget, apt-get update, etc). I'll get the whole syn->syn/ack->ack process, but after that, I no longer get incoming traffic via this connection. Using etherreal, I can see that the next packet is coming into my computer, but it is getting dropped by iptables? If I stop the firewall, all traffic comes through and I can download the needed data. So I thought it was something in my firewall. But then I noticed that if I open mozilla firefox or links and type in http://ftp.egr.msu.edu/, everything works great with the firewall on. But still no traffic via the wget. Sample ruleset: #Allow for updates/downloads via apt-get iptables -A OUTPUT -o eth0 -p tcp --dport http -d ftp.egr.msu.edu -m state --state NEW,ESTABLISHED -j ACCEPT iptables -A INPUT -i eth0 -p tcp --sport http -s ftp.egr.msu.edu -m state --state ESTABLISHED -j ACCEPT Any idea why iptables would block some command line utilities, but not firefox and links? Sites for which there are no exceptions for in iptables, such as google, don't work in firefox or on the command line.
