Linux Firewall Runlevel Question
 

I was looking at the /etc/inittab file and was wondering if it were possible to run my firewall in runlevel 2 instead of 3. Are there any repercussions in that?

From what the /etc/inittab stated, it looked like runlevel 2 doesn't bring up networking. However testing this on another server, runlevel 2 did have networking support and i could ping my other servers.

Running RH 7.3.

Thanks,

g

It depends on a distro. RH doesn't start network on runlevel 2, but Debian does... In fact, you can configure it. You can also bring your firewall up on both 2 and 3.

The runlevels are somewhat distro specific. I am pretty sure that runlevel 2 on Red Hat systems does not start the network (unless you tweak it) and therefore there's no need to start the firewall. On Debian I think, however, runlevel 2 does start up the network. I'm not entirely sure though. So unless your server explicitly starts the network on runlevel 2 you don't need to worry. You can check this by seeing the the network startup script is linked from /etc/rc.d/rc2.d. If it is, runlevel 2 starts the network. If not, it does not.