iptable

nimic · 10-09-2019, 05:49 AM

hi,
i like to understand the following.
iptables -A OUTPUT -d 192.168.30.0/24 -o eth0 -m owner --gid-owner test -j ACCEPT

is this mean that only users who belong gid test and reside in server from 192.168.30.0 can have acces in this server (where the iptables exist) using tcp protocol?the user can coonect through ssh to this server?
thank you

berndbausch · 10-09-2019, 05:56 AM

This clause means:
- certain packets are allowed to leave the local system
- their destination address is from the range 192.168.30.0/24
- they were generated by a process whose group is test.

The man page warns that some packets don't have an owner and will therefore be blocked. This includes packets that are generated by the kernel, for example ICMP echo replies.