Multiple IPs on server; use iptables to allow access to port on only one IP

June 1, 2019 197 views
Firewall CentOS

Hi,

I have a CentOS 7 server running Plesk. The server has 5 IPs attached to it. I want users to only be able to access Plesk’s port (8443) from one of the IPs.

How can I do this using iptables?

My current rules look like this:

-P INPUT DROP
-P FORWARD DROP
-P OUTPUT DROP
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m state --state NEW -j REJECT --reject-with tcp-reset
-A INPUT -m state --state INVALID -j DROP
-A INPUT -i lo -j ACCEPT
...
-A INPUT -p tcp -m tcp --dport 8443 -j ACCEPT
...
-A INPUT -j DROP
1 Answer

You can block incoming TCP/UDP connections on port 8443 for those IP addresses or just close the port via the Firewall.

You can follow this article on Plesk website:

https://support.plesk.com/hc/en-us/articles/115001078014-How-to-manage-firewall-rules-on-a-Plesk-for-Linux-server

Alex

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