[TriLUG] IPTABLES rule help

[bp]

Hi guys,

Need a quick iptables rule help if you don't mind.

Goal.
Allow anything from 10.17.23. , 10.17.24 (both /25 subnets) and 10.32.8. 
(a /23 subnet.)

Deny everything inbound from outside of those 3 subnets except for SSH and 
pings.

I'd still like to be able to fwd X and anything outgoing to anywhere.

Any pro's have a 3 or 4 line ruleset for that order?

Thanks, bp