you can ckeck /var/log/lfd.log file to find whether the ip is blocked or not, by using
grep <ip> /var/log/lfd.log
If it blocked you need to do the following step to remove that block
csf -tr <blocked ip>
Then you must restart the csf firewall.
csf -r
2) How to remove permanent ip block:
you can check /etc/csf/csf.deny file to find whether the ip is blocked or not.
grep <ip> /etc/csf/csf.deny
If it blocked you need to do the following step to remove that block
csf -dr <blocked ip>
Then you must restart the csf firewall.
csf -r
