ufw blocks IPv6 connections

**ygoe** · January 10th, 2011

Hi,

I've just started using ufw with the frontend gufw. I've configured it like this:

Accept everything in and out as default
Block incoming FTP connections from a certain IPv4 address (brute-force for days)

Today I noticed that IPv6 connections don't work anymore. The connection to two hosts (IPv6 only) times out. As soon as I disable ufw entirely, the connections work again. The host I want to connect to is:
2001:638:a00:f00b:200:1cff:fedb:d38f port 7337
2001:638:a00:f00b:a00:6ff:fe07:cda2 port 7337
These are small telnet servers that print out a number (temperature nearby) and close again. I'm logging those values in a database.

Is ufw not IPv6-capable and blocks things it's not supposed to?

Update: ufw seems complete garbage to me... You can't even configure it while it's disabled! How am I supposed to safely activate it when the first thing it does is blocking all communications? I can't even configure it to let me in before I configure it to keep me out... And then, even if I explicitly let it pass port 7337, it still blocks it through IPv6. While the idea is certainly nice, I don't think this could be useful to me. I guess I need to write my own rufw (really uncomplicated - and working).

**PatchesTheCaveman** · January 11th, 2011

Edit your /etc/default/ufw file and change the line that says:

Code:

IPV6=no

to

Code:

IPV6=yes

**ygoe** · January 11th, 2011

Thanks, that seems to help. I wonder what this firewall also blocks if not configured otherwise in some config files documented in a hidden spot... Time will tell.