how to use ipt_limit.o?

["Peter" <chenlf@xxxxxxxx>]

i am using redhat73 kernel 2.4.18-18.7 
i want to limit number of httpd access per/client 
i use 
# insmod  ipt_limit.o
# iptables -A INPUT -p tcp --syn --dport http -m iplimit --iplimit-above 4 -j REJECT
then i get error:
iptables: No chain/target/match by that name
who can help me