Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I thought to have a simple ipv6 firewall, but it turned out to be hell. Somehow I really can't connect with any ipv6 from my machine unless I set INPUT Policy to ACCEPT. Below my current ip6tables

ip6tables -L

Chain INPUT (policy DROP)
target     prot opt source               destination
ACCEPT     all      anywhere             anywhere           state RELATED,ESTABLISHED
ACCEPT     ipv6-icmp    anywhere             anywhere
ACCEPT     tcp      anywhere             anywhere           tcp dpt:http
ACCEPT     tcp      anywhere             anywhere           tcp dpt:https

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

If I try to connect with any ipv6 adres it doesn't work?

telnet 80
Trying 2a00:1450:4013:c00::76...


telnet 443
Trying 2a00:1450:4013:c00::76...

When I set:

ip6tables -P INPUT ACCEPT

It works.. but then.. well then everything is open? what is going on? Help?

share|improve this question

You're probably missing the critical "stateful" rule:


You are also missing a rule to accept ICMPv6. Without ICMPv6, IPv6 simply does not function.

-A INPUT -p ipv6-icmp -j ACCEPT

For performance reasons, this should be among the earliest rules in your chain.

share|improve this answer
Noope that did not work.. i flushed the input rules and first added your rule: -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT -A INPUT -i eth0 -p tcp --dport 443 -j ACCEPT – klaas Aug 31 '12 at 8:57
Oops, I forgot something. See the updated answer. – Michael Hampton Aug 31 '12 at 9:16
i updated my post in the top, but no result... i did both the things you mention, you can see the ip6tables -L in the top – klaas Aug 31 '12 at 9:29

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.