How to tell if I'm running a firewall?

PaulBx1 · 2012-10-25 02:06:03

When I installed arch a while ago (a year?) I was pretty sure I added a firewall. However now when I issue the "iptables" or "iptables -nvL" command it says "command not found". I don't recall what front end I (supposedly) installed. I did change to systemd in the meantime, maybe that is what caused it to go awol.

It was not crucial because I am behind a router, but now that my son is punching holes in the router firewall for his games, I'd like to fix this situation.

A couple of things confuse me. If iptables is part of the kernel then I shouldn't have to install it, right? But then it should respond to "iptables -nvL" I would think.

Also I wonder if I have a front end even if there is no iptables. I did try "pacman -Qs firewall" and got nothing. Also when I did "pacman -Ss firewall" I found a few front ends like shorewall and ufw but no iptables.

Last edited by PaulBx1 (2012-10-25 02:07:09)

WonderWoofy · 2012-10-25 02:07:53

It makes me curious as to why you did not do $ pacman -Ss iptables ?

PaulBx1 · 2012-10-25 02:22:36

Guess I just assumed the description for iptables would have "firewall" in it. Silly me.

Well I must have been hallucinating that I had a firewall before. Anyway there is none now that I can tell ("systemctl" does not display anything having to do with firewalls or iptables either). So, I suppose I will just install a firewall and front end as if I never had...

ConnorBehan · 2012-10-25 05:01:11

I imagine the situation with iptables is similar to udev. Support for it is built into the kernel but you still need to install a userspace program in order to take advantage of it.

hunterthomson · 2012-10-25 07:04:10

Well ya, iptables and Netfilter is part of the Kernel, but you configure it with userspace tools.

You had it right you tell what rules are configured with the command: iptables -nvL

Personaly, I love arno-iptables-firewall script that is in the AUR. It makes it vary easy to do NAT, Port-Forwarding, and everything you would ever want. It also makes vary secure rules to prevent all kinds of attacks. I really could not do a better job myself. I found that basicaly all the GUI "firewall" iptables configuration programs only set vary basic rules.

This is the systemd unit file I use to start/stop
/usr/lib/systemd/system/arno-iptables-firewall.service

[Unit]
Description=Arno iptables firewall

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/sbin/arno-iptables-firewall start
ExecStop=/usr/sbin/arno-iptables-firewall stop

[Install]
WantedBy=multi-user.target

You configure it by editing /etc/arno-iptables-firewall/firewall.conf

Strike0 · 2012-10-25 19:51:34

Another easy to setup tool for iptables is: https://wiki.archlinux.org/index.php/Ufw
or more generally have a look at: https://wiki.archlinux.org/index.php/Firewalls

Arch Linux

#1 2012-10-25 02:06:03

How to tell if I'm running a firewall?

#2 2012-10-25 02:07:53

Re: How to tell if I'm running a firewall?

#3 2012-10-25 02:22:36

Re: How to tell if I'm running a firewall?

#4 2012-10-25 05:01:11

Re: How to tell if I'm running a firewall?

#5 2012-10-25 07:04:10

Re: How to tell if I'm running a firewall?

#6 2012-10-25 19:51:34

Re: How to tell if I'm running a firewall?

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