Hi All, Seeing as though this query is not 100% Fedora related it may be better if someone is able to help me with this query if they reply to me personally off-list. On reading the post made recently by Thom, it got me thinking ... At the school I work out we have a setup where we have 2 computer laboratories (primary-lab & secondary-lab -- each lab contains about 40 machines) and a rather large number of computers scattered throughout classrooms. Everything runs from a DHCP router which supplies each machine with its required network details. The machines scattered throughout the school (non-lab machines) has the following details: IP-Address: 10.10.?.* -- ? starts at 2 subnet-mask: 255.255.0.0 The machines in the computer labs have the following details IP-Address: 10.10.2.* subnet-mask: 255.255.255.0 The discretion of whether a machine receives the B or C-class subnet mask is based on MAC addresses. What has confused in the fact these two networks can talk to one another. Is it because the admin has freed up the firewall between the two, but I can't really see the point of specifying two seperate masks and then opening up the firewall to additional traffic. Was wondering if someone might be able to shed some light into either why this happens (or shouldn't happen :P ) in the world of networking. Thanks for your help. All the best. Cheers, Tony Crouch
