I went to reload (iptables-restore) my iptables configuration and obtained an error at the COMMIT statement. No further details were provided even when I ran restore with the -v option.
I determined that none of my backed up configuration files going back to October will load either. This is more than passing strange because I altered and uploaded the iptables configuration on this host several times in December alone. These alterations certainly applied without error at the time.
Through painful trial and error (it is a fairly large configuration) I discovered that I cannot add any rule using the __recent__ module. Adding a single rule referencing that module inevitably results in a load error reported at the following COMMIT statement. An example of an actual rule that fails follows:
. . . :BRUTE_FORCE - [0:0] . . . -A BRUTE_FORCE -p tcp -m tcp -m state -m recent --set -i eth0 --dport 22 --state NEW -A BRUTE_FORCE -m comment -j RETURN --comment "Return to calling chain" COMMIT
Perhaps I am missing something obvious but as far as I can determine the rule using the recent module should simply add all traffic coming in over i/f eth0 consigned to port 22 on any ip-addr to the DEFAULT list. I do not expect it to give an error. If I remove this statement then the iptables file loads without error.
An interesting thing happens if I simply add a trailing -j to the end of recent module rule above. It fails with this specific error:
-c packet counter not numeric
Does anyone see what I am doing wrong?
Sincerely,