Network configuration

[Michał Masłowski]

I have problems with network configuration of two computers with FreeBSD. One 
has 5.4 and the second has 6.0. Both have Pentium III compatible processors. 
They are both connected to an Ethernet switch.
Computer with 5.4 has access to WAN, but there isn't any access to computer 
with 6.0.
How should I configure LAN between these two computers?
I'd be grateful if you could help me.