Local Network with fast3302I

I (my familly) presently use a Sagem Fast3302 gateway to connect three PC to the internet.
It’s OK for that part.

I would like to use this Sagem Fast3302 to share information locally from PC to PC (all suse11.0).
1- is it possible?
2 If yes, is there any tutorial or guide to help me? I am relatively newbie in this field.