Iptables and LAN

[Arlana Alea]

Hi,

I set up my firewall with iptables on a Redhat 7.1 Linux 2.4 OS.
The server with the firewall isn't able to communicate with another
system that is
on the local area network.  I tried to ping the other system from the
server and it failed.
I added this line:
    LAN_IFC=local area network interface
    iptables -A INPUT -i $LAN_IFC -j ACCEPT
and then I'm able to ping the other system.

But then I tried to print something from the server and it didn't print.
It spooled but
it didn't print out.  I turned off the firewall and able to print.

If I execute commands locally it shouldn't go through the firewall -
right?
Anyone else encounter this problem or suggestions for a fix?

Thanks in advance!  Have a great day!

-LaNi