Network Security

How to unblock blacklisted IP addresses on a WHM based GNU/Linux server

On certain servers, there are chances of our IP addresses getting blocked when we accidentally enter the wrong password multiple times or when we unintentionally try to ssh via the wrong port multiple times. The IP will be blocked for a certain period of time. If you have faced the same issue then read on to know how to block blacklisted IP addresses on a WHM based GNU/Linux server.

How to find out the current port being used by SSH on a WHM based server

Most web developers & system administrators have to do SSH logins to WHM based servers to make the necessary changes there. The default port used for ssh logins is port 22. However there might be unusual circumstances where port 22 is not the default port. In such a scenario we need to identify the default ssh-port used by the server. If you are facing a similar situation then read on to know how to find out the current port being used by SSH on a WHM based server.

Find all active IPs your local network using nmap

Nmap is a Free Software tool that can be used for a variety of network network exploration tasks and security auditing. Nmap ("Network Mapper") scans IP packets to determine a lot of different aspects about hosts available on the network and also about services these hosts are offering. It can help you find a lot of information about these hosts including reverse DNS names, operating system guesses, device types, and MAC addresses.