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issue with iptables blocking connections.
| Posted by ldl, 02-25-2011, 12:21 PM | | I'm having an issue with iptables on my vps. Previous to now my iptables rules have been working untouched for almost 5 years. I haven't changed anything but all of a sudden things don't work. I can ssh into the vps but traceroute doesn't work, ping doesn't work, dig doesn't work, of course name resolution doesn't work and neither does sending email.
If I'm watching tcpdump during a traceroute it seems like my requests are going out but nothing is coming back.
I replaced my iptables with this super simple chain for testing
Even that fails and the only way anything works is to change to input accept and flush the rules.
So I'm pretty sure states aren't being detected properly.
my questions:
1. has something changed with a recent kernel or upgrade that would prevent that from working
2. is there something I can do that's similar to state but may work?
I've opened a ticket with my provider but I'm getting nowhere with them they insist the firewall works but seemingly haven't tried using anything.
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| Posted by Rapid2214, 02-25-2011, 06:48 PM | | Did you recently update your server?
Seems strange, does everything work if you disabled the firewall temporally?
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| Posted by ldl, 02-25-2011, 10:25 PM | | Nope I haven't updated anything since the end of January so it's been working fine for at least 3 weeks since then. If I disable the firewall everything returns back to normal. The only thing else I can think of is the provider did something on the vps host node, or there's been some other change I'm unaware of. But Since I'm getting the run around from them I thought I'd ask if there was something I'm missing here.
Last edited by ldl; 02-25-2011 at 10:29 PM.
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| Posted by asciiDigital, 02-26-2011, 01:22 AM | | Have you tried reinstalling iptables?
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| Posted by madaboutlinux, 02-26-2011, 04:13 AM | | It should be an update on the host server causing problems. If you are sure your iptable rules are correct, then only your host can solve the problem. Was the host server rebooted recently? Check the uptime OR the last logs of your VPS and see if it was rebooted just before the problem started.
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