alternative to firestarter?

[debian]

hey all,

im looking for a good alternative to fire starter. After my system got
attacked a couple days ago (The guy was doing an oldschool attack using
vnc to "attempt" to install his windows virus onto my machine...and yes
i found reports of this on google), i decided to put a fire wall on my
system and the only firewall that i know of is firestarter, however
firestarter gives me a lot of core dumps and crashes very often

im just looking for a more stable firewall...suggestions are welcome

--cj