[Zope] zserver 1 session default?

[Milt Martin]

Trying to access zserver/zope pages:
1. At home I dialed up up my ISP to connect to internet
2. I launched zserver and recorded my ip address
3. I went to work
4. I successfully accessed/browsed my zope pages from my work PC(neat!),
but...
5. I attempted to have others access zope from their pc's and NOCANDO?
I could continue to access but they could not.
Why only 1 incoming ip address for zserver at a time?
Using vers 2.1.1 on Redhat Thanks.