I've the following question: How can I close all ports except port 22. nmap shows me all used ports:
nmap localhost Starting Nmap 7.01 ( https://nmap.org ) at 2017-02-20 20:06 CET Nmap scan report for localhost (127.0.0.1) Host is up (0.0000050s latency). Other addresses for localhost (not scanned): ::1 Not shown: 999 closed ports PORT STATE SERVICE 22/tcp open ssh Nmap done: 1 IP address (1 host up) scanned in 0.08 seconds
netstate displays open connections:
sudo netstat -tulpen | grep -v '127.0.0.1' | grep -v '::1:' Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State User Inode PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 0 160309215 286/sshd tcp6 0 0 :::22 :::* LISTEN 0 160309218 286/sshd
but these 999 are not really closed they are not in use.
iptables -L gives:
Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination
so every port is open now.
Since this is an external server I have to keep port 22 open, since I use the ssh connection via port 22 during changing the settings.
What might be the best way to configure this?
Can I stop iptables and better start firewalld and make there configurations? Or can I temporarily stop iptables, make changes and then restart iptables?
Or are there some configuration files, that I can edit?
I'm not really familiar with these configurations, but I have to do that carefully and correctly.
Thanks in advance for your help!