[NCLUG] Iptables - ip range

[Jesse Courchaine]

Hi,

If anyone is knowledgable in iptables, I have a question for you.  I
would
like to select a range of IP addresses (i.e. 10.10.10.30 - 10.10.10.60,
not a subnet)
for use in the source of an iptables based firewall.  The only way I
know
how to do this is using a shell for-script to go through each address
and add
a rule for each one (as opposed to a subnet where only one rule is
needed)

Ex.
Iptables -A INPUT -S 10.10.10.30 -i eth0 -p tcp --dport 21 -j ACCEPT
Iptables -A INPUT -S 10.10.10.31 -i eth0 -p tcp --dport 21 -j ACCEPT
Iptables -A INPUT -S 10.10.10.32 -i eth0 -p tcp --dport 21 -j ACCEPT
...

Does anyone know if there is another way to do this? And if not, will it
slow the machine down to have to search through all the ~30 rules?

Thanks,
Jesse