DenyHosts is a security tool for Linux and Unix systems that helps protect against brute-force attacks by blocking IP addresses that make excessive failed login attempts.
To remove or delete an IP address from the DenyHosts blocklist, you can edit the /etc/hosts.deny file and remove the line that corresponds to the IP address you want to unblock.
For example, if the /etc/hosts.deny file contains the following line:
sshd: 123.456.789.0
This means that the IP address 123.456.789.0 is blocked by DenyHosts. To unblock this IP address, you can simply delete this line from the /etc/hosts.deny file.
You can also use the denyhosts-remove script to remove an IP address from the DenyHosts blocklist. This script is usually installed in the /usr/sbin or /usr/local/sbin directory.
To use the denyhosts-remove script, you can run the following command:
denyhosts-remove 123.456.789.0
This will remove the IP address 123.456.789.0 from the DenyHosts blocklist.
Keep in mind that removing an IP address from the DenyHosts blocklist does not necessarily mean that the IP address will be able to access your system. It is still possible for other security measures, such as a firewall or IPTables rules, to block the IP address.
For more information about how to remove or delete an IP address from the DenyHosts blocklist, you can consult the DenyHosts documentation or seek assistance from a qualified Linux or Unix administrator.