Iptables on gateway

broadjos · 10-16-2018, 05:30 AM

1)..................................
I hav several clients to this gw.
I want to use IPTABLES for firewall. I downloaded n installed.
iptables comand is working on prompt.

linux> service iptables status
service: no such service iptables

what could be problem???

2)---------------------------

Also if i flush iptables tables to write my own, thn this comp is getting disconnected from LAN

linux> ping 172.31.1.1
PING 172.31.1.1 (172.31.1.1) 56(84) bytes of data.
64 bytes from 172.31.1.1: icmp_seq=1 ttl=63 time=0.517 ms
64 bytes from 172.31.1.1: icmp_seq=2 ttl=63 time=0.501 ms
64 bytes from 172.31.1.1: icmp_seq=3 ttl=63 time=0.504 ms

--- 172.31.1.1 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.501/0.507/0.517/0.019 ms

linux> iptables -F
linux> ping 172.31.1.1
no response
............................................

lougavulin · 10-16-2018, 10:18 AM

1) What is your distribution ?
Because you may have to install a package and you should probably use systemd command.

2) What are your iptables rules and your network config ?

agillator · 10-16-2018, 05:18 PM

Not knowing your distribution is a problem. My guess, speaking generically, is that you have iptables installed but not an iptables-services package which would give you the services file required to run it under systemd. Flushing your rules should leave your policies intact. What are they? I'll bet they are DROP across the board. That would certainly do it. Try running iptables -L -v -n --line-numbers > rules as root (or sudo or the equivalent) and then look at the file named rules. That should tell you a lot including your policies.

You probably should either install iptables-services or write your own services file. It isn't that hard to write a simple one. Look at a few .service files on your computer until you find a fairly simple one you can copy and modify. Most of the commands are pretty obvious but looking at the man page for systemd should get you started. Remember that when you add, delete or change a service file you need to reload (sudo systemctl daemon-reload). Then when it is right, sudo systemctl enable <service file name> to allow it to run automatically.