ConfigServer Community Forum

I installed CSF (8.01) on my new Debian 8 server. However, I am unable to start the csf service when IP6 is enabled in the csf configuration. I get the following error:
ip6tables v1.4.21: can't initialize ip6tables table `nat': Table does not exist (do you need to insmod?)
Perhaps ip6tables or your kernel needs to be upgraded.

Here's the full output from the restart:

Restarting csf...

Flushing chain `INPUT'
Flushing chain `FORWARD'
Flushing chain `OUTPUT'
Flushing chain `ALLOWIN'
Flushing chain `ALLOWOUT'
Flushing chain `DENYIN'
Flushing chain `DENYOUT'
Flushing chain `INVALID'
Flushing chain `INVDROP'
Flushing chain `LOCALINPUT'
Flushing chain `LOCALOUTPUT'
Flushing chain `LOGDROPIN'
Flushing chain `LOGDROPOUT'
Flushing chain `PREROUTING'
Flushing chain `INPUT'
Flushing chain `OUTPUT'
Flushing chain `POSTROUTING'
Deleting chain `ALLOWIN'
Deleting chain `ALLOWOUT'
Deleting chain `DENYIN'
Deleting chain `DENYOUT'
Deleting chain `INVALID'
Deleting chain `INVDROP'
Deleting chain `LOCALINPUT'
Deleting chain `LOCALOUTPUT'
Deleting chain `LOGDROPIN'
Deleting chain `LOGDROPOUT'
Flushing chain `INPUT'
Flushing chain `FORWARD'
Flushing chain `OUTPUT'
ip6tables v1.4.21: can't initialize ip6tables table `nat': Table does not exist (do you need to insmod?)
Perhaps ip6tables or your kernel needs to be upgraded.

ip6tables v1.4.21: can't initialize ip6tables table `nat': Table does not exist (do you need to insmod?)
Perhaps ip6tables or your kernel needs to be upgraded.
open3: pipe(GLOB(0x2665998), GLOB(0x26659b0)) failed: Too many open files at /usr/sbin/csf line 4620.
...Done.

Restarting lfd...

Job for lfd.service failed. See 'systemctl status lfd.service' and 'journalctl -xn' for details.
...Done.

lfd won't start because I haven't turned off testing mode yet. So I'm not concerned about that right now.

I tried doing some google searching about the ip6tables error but couldn't find a solution.
Version is: ip6tables v1.4.21

Are you running the latest kernel? We do not see any issues on our test server:

I have no idea. It's Debian 8. Here's the output from that command:
Linux web.fosterclub.com 3.12.27-xenU #1 SMP Thu Aug 28 23:13:07 UTC 2014 x86_64 GNU/Linux

That is an old non-native kernel and why it is not working. You either need an updated kernel from your virtual server provider or disable IPV6.

Thanks, I'll get in touch with tech support. Their VPS management web interface has a kernel selector and I chose the most recent version offered except for a version 4.0 which was labeled as "experimental". I was afraid to choose that one since this server will go into production eventually...!

We'll put in a workaround in the next release of csf (due today) that will allow IPV6 support even if the nat table is missing.

Tech support at my host told me to try the 4.0 kernel and it works. No more issues with ip6tables. Thanks for your help!