One of the easiest ways to restrict SSH access by IP address is to modify the sshd_config file, which controls SSH server settings. By following these tips and taking a proactive approach to server security, you can reduce the risk of security breaches and ensure the continued operation of your systems. Now, when listing the rules, the rule to allow HTTP is no longer listed, because we restored iptables from the /etc/sysconfig/iptables file.In this blog post, we’ll discuss methods to restrict SSH access to your Linux server by IP address and then also some SSH hardening that you should already have in place but still worth mentioning in case you do not.Īs the number of cyber attacks continues to rise, it’s crucial to prioritize server security and implement best practices for server management. iptables-restore < /etc/sysconfig/iptables

Let's issue the iptables-restore command. However, the /etc/sysconfig/iptables file will not include the rule to allow HTTP, since the iptables-save command was not used after adding the rule to allow HTTP. Pkts bytes target prot opt in out source destinationĠ 0 ACCEPT all - lo any anywhere anywhereĠ 0 ACCEPT tcp - any any anywhere anywhere tcp dpt:http Now, when you use the list the iptables rules, the rule to allow HTTP on port 80 will be listed. iptables -I INPUT -p tcp -dport 80 -j ACCEPT In this example, a rule is added to allow HTTP on port 80. Now let's say you add a rules to iptables. A OUTPUT -p tcp -m tcp -sport 22 -m conntrack -ctstate ESTABLISHED -j ACCEPT A INPUT -p icmp -m icmp -icmp-type 8 -j ACCEPT

A INPUT -s 192.168.0.0/24 -p tcp -m tcp -dport 22 -m conntrack -ctstate NEW,ESTABLISHED -j ACCEPT

The /etc/sysconfig/iptables file will now have something like this. Let's say you have used the iptables-save command to save your current iptables rules to the /etc/sysconfig/iptables file, like this.

Iptables reload