iptables attack blocking

[MC12]

Hi, not sure if iptables don't work or I am doing some thing wrong when I block an length of attack from firewall tap it work fine but when I try to block the same length from iptables It don't work the command I have used.
iptables -I INPUT -p udp -m length --length 62 -j DROP
same thing with hex string when I block from firewall it work but from iptables it won't
any advice ?

thanks

[Edge100x]

How are you testing whether it works? Are you looking at the "iptables -nvL" output?

[MC12]

How are you testing whether it works? Are you looking at the "iptables -nvL" output?

When the attack is I tried to make rule to block that length From firewall tab after that the attack packets got dropped and fine , then I tried to delete that rule and block it from Iptables the same attack won't block till I block it from firewall tab..