fail2ban-client:tldr:9c2b8

This command uses the fail2ban-client utility to unban an IP address from a specific jail. Here is a breakdown of its components:

1. fail2ban-client: This is the command-line utility for managing Fail2Ban, a log-parsing application that helps protect servers from malicious activity.

2. set: This subcommand is used to modify a specific aspect of Fail2Ban, in this case, to unban an IP address.

3. ${jail}: This variable represents the name of the jail from which the IP address should be unbanned. In Fail2Ban, jails are predefined configurations that specify which logs to monitor and what actions to take when certain patterns are detected.

4. unbanip: This is the action being performed. It instructs Fail2Ban to remove the ban on the specified IP address.

5. ${ip}: This variable represents the IP address that should be unbanned. Replace ${ip} with the actual IP address you want to remove from the ban.

By executing this command and providing the appropriate values for ${jail} and ${ip}, Fail2Ban will remove the ban on the specified IP address within the specified jail, allowing connections from that IP again.