I'd personally attempt to avoid thin ethernet (10Base2 - which is 50 ohm co-axial cable with locking BNC connectors on the end - similar but not the same as TV co-axial and the cable is very different electrically so *never* attempt to use TV cable for this). 10Base2 works fine when it works... when theres a problem its very difficult to isolate just where the problem is - a single poorly wired connector can make a machine at the other end of the cable misbehave for example. Basically 10Base2 is unsupportable in a hostile environment - such as a school :-) You can get 10/100BaseT PCI cards (twisted pair cabling with RJ45 plugs on each end - RJ45 are 8 way plugs made of clear plastic with a central locking clip on the opposite side of the plug to the connectors. They are similar to BTs phone plug but not the same or interchangable) for a cost of less than 10 pounds per card. Choose your cards relatively carefully as some types are more supportable and reliable under linux than others (I would give a specific card recommendation but I don't have web access right now). These cards have 100BaseT capability which might be useful later You need a hub for more than 2 10/100BaseT devices. Cost of this is roughly the same per-port as cheap cards. Unfortunately for your 25 machines thats looking like around 500 pounds plus the cable itself. BTW for those just setting up a small network, with ISDN network access, look carefully at the small office networking kit - ie DLink 206 ISDN router, which does DHCP and provides external access etc and has an embedded 10BaseT hub for just over a hundred quids. Nigel. -- [ - Opinions expressed are personal and may not be shared by VData - ] [ Nigel Metheringham Nigel.Metheringham@VData.co.uk ] [ Phone: +44 1423 850000 Fax +44 1423 858866 ]