iptables – GTKC Knowledgebase

kernel: conntrack: generic helper won’t handle protocol 47.

by admin : September 6, 2021September 6, 2021 Debian, iptables, Linux

I was getting the following message in my log files on my Debian firewall. kernel: conntrack: generic helper won’t handle protocol 47. Please consider loading the specific helper module. The nf_conntrack_proto_gre module needs to be loaded to resolve this. modprobe nf_conntrack_proto_gre To load it automatically at boot, I created a new file (gre.conf) in /etc/modules-load.d […]

Debian iptables Linux ulog ulogd2

iptables with ulogd quick howto

by admin : December 19, 2017July 16, 2021 Debian, iptables, Linux, ulog, ulogd2

I wanted to enable ulogd for my firewall logging, but after finding several sites with examples, none of them worked for me. So after gathering snippets of info from various sites, I managed to put a working configuration together, which is what you see here. This is on Debian 8.9 (Jessie) Install ulogd (ulogd is […]

iptables Linux

Blocking bogons with iptables

by admin : July 8, 2015July 11, 2017 iptables, Linux

ipsets is a fairly recent addition to the netfilter family. It is possible to define networks / addresses and then use them in iptables. ipset –create bogons nethash ipset –add bogons 10.0.0.0/8 ipset –add bogons 192.168.0.0/16 ipset –add bogons 0.0.0.0/8 ipset –add bogons 169.254.0.0/16 ipset –add bogons 172.16.0.0/12 ipset –add bogons 192.0.2.0/24 ipset –add bogons […]