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Support #2742

closed

help with inline IPS

Added by jeremy d about 6 years ago. Updated over 5 years ago.

Status:
Closed
Priority:
Normal
Affected Versions:
Label:

Description

Hello! I am trying to have suricata be inline and block on 2 interfaces eth0 and eth1. eth0 is my gateway and eth1 is providing DHCP downstream. I have it blocking on the external interface with the following commands, yet it only alerts on inbound going out traffic.

modprobe br_netfilter
ifconfig eth1 192.168.22.1 up
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A FORWARD -t mangle -j NFQUEUE --queue-bypass
echo 1 > /proc/sys/net/ipv4/ip_forward
Actions #1

Updated by Victor Julien about 6 years ago

  • Tracker changed from Bug to Support
  • Affected Versions deleted (4.0beta1)

I don't think the mangle table is meant for this purpose. The filter table is where the NFQUEUE rule should be.

Please see this guide https://suricata.readthedocs.io/en/suricata-4.1.0/setting-up-ipsinline-for-linux.html

Actions #2

Updated by jeremy d about 6 years ago

Victor Julien wrote:

I don't think the mangle table is meant for this purpose. The filter table is where the NFQUEUE rule should be.

Please see this guide https://suricata.readthedocs.io/en/suricata-4.1.0/setting-up-ipsinline-for-linux.html

Thanks for the help Victor! That guide is helpful if i want to make it inline, but I cant seem to also have the IPS get an IP address. I have a setup where Router/Gateway <-> Suricata (with DHCP IP) <-> Router2 (NATed IP from Suricata) but I can only get traffic from router2 outbound.

Actions #3

Updated by jeremy d about 6 years ago

This is my updated bas script I am using

modprobe br_netfilter
ifconfig eth0 0.0.0.0 up --arp
ifconfig eth1 0.0.0.0 up --arp
brctl addbr br0
brctl addif br0 eth1
brctl addif br0 eth0
brctl stp br0 off
ifconfig br0 192.168.22.1 up --arp
dnsmasq --interface=br0 --dhcp-range=br0,192.168.22.2,192.168.22.6,12h
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -I FORWARD -j NFQUEUE --queue-bypass
echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
Actions #4

Updated by jeremy d about 6 years ago

So i was able to get the routing to work properly but suricata only watches and blocks on traffic when packets are leaving the LAN port and not on my WAN port with the following configs

modprobe br_netfilter
ifconfig eth0 0.0.0.0 up
ifconfig eth1 192.168.22.1 up
dnsmasq --interface=eth1 --dhcp-range=eth1,192.168.22.2,192.168.22.6,12h
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -I FORWARD -i eth0 -o eth1 -j NFQUEUE --queue-bypass
iptables -I FORWARD -i eth1 -o eth0 -j NFQUEUE --queue-bypass
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward
Actions #5

Updated by Victor Julien almost 6 years ago

  • Assignee set to Community Ticket
Actions #6

Updated by Andreas Herz over 5 years ago

  • Target version set to Support
Actions #7

Updated by Andreas Herz over 5 years ago

You could try to set dedicated queue numbers (--queue-num) and attach suricata to both. You could also test with suricata running on only one of those if both NFQUEUE jump targets really work.

Actions #8

Updated by Andreas Herz over 5 years ago

  • Status changed from New to Feedback
Actions #9

Updated by Victor Julien over 5 years ago

  • Status changed from Feedback to Closed
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