Iptables: Unblock / Delete an IP Address Listed in IPtables Tables in Categories BASH Shell, CentOS, Debian / Ubuntu, Iptables, Linux, Security, Suse, Troubleshooting, Ubuntu Linux last updated February 15, 2011Q. I am a brand new user of a Linux iptables and I can’t find how to instruct my iptables to delete or unblock an IP address listed in iptables firewall. I’m using Debian Linux version. Can you help please?