Trying to block a certain http/https URL request from hitting the server by adding this rule to iptables:
iptables -I INPUT 1 -p tcp -m multiport --destination-ports 80,443 -m string --string "my_string" --algo bm -j DROP
This returns the following error:
No chain/target/match by that name
I can add other rules to the INPUT chain no problem. I believe I've identified the culprit as the string module, but to me the syntax looks fine.