Can I put my head above the parapet to put forward some insomniac speculations and a prediction to explain why I keep on about using the long-awaited router without cloning and why I have such reservations about using "sudo ifconfig" in the way suggested?
BTW
Stripes, did you originally connect the G3 through the set-top box (STB) and later get given a stand-alone cable modem (SACM)?
All the original problems, with not one but two iMacs failing to pick up an IP address and reverting to the self-assigned 169. address and, more significantly, not being able to be jolted out of that state, would be consistent with the cable system treating your SACM as though it was (the modem part of) your STB. STBs are "provisioned" to work only with a single client MAC while the system allows SACMs to work with a change of client machines. The prediction is that the Belkin router will not connect with its "native" out-of-the-box MAC setting but will connect when you "clone" the G3's MAC number into it.
Now some thoughts about why MAC "spoofing" with a directly-connected machine might not be exactly equivalent to MAC "cloning" with a gateway router: bear in mind that I am not an IT professional and what little I knew about networking has already been increased by learning that OS X now allows spoofing!
The MAC number is intended to be unique to each Media Access Controller and unalterable as it is "burnt in silicon". "Spoofing" is, after all, usually done for nefarious purposes. The cable system interrogates the Media Access Controller of whatever equipment is directly connected to the SACM and gets back "packets" that contain, among other things, the MAC number of the Media Access Controller. Now, although a connected computer's operating system can be "hacked" to cause IP packets originated by the machine to contain a "soft" MAC number instead of the Media Access Controller's "hard" MAC number, it doesn't necessarily follow that its Media Access Controller will respond to incoming interrogations with packets containing the "soft" MAC number (because Media Access Controllers are designed to be largely autonomous so as to "take the load off the CPU". This is why ethernet connections are vastly superior to USB connections in the context of networking.)
A home gateway router is, however, rather different. Its Media Access Controller is specifically designed to be "programmable" to take account of those ISPs who try to restrict access to a single computer by reference to its MAC number. If cloned with a client machine MAC number, a home gateway router _must_ respond to interrogation with packets containing the new MAC number and indeed use that MAC number under all circumstances.
To sum up- on
Stripes behalf, I was reading Ted Landau's monumental tome "Mac OS X Helpdesk" yesterday (!) and he goes so far as to state that "99% of problems when connecting Macs to broadband are the fault of the ISP" and I'm sure that is the case here. However, I don't see how to get VM/ntl to acknowledge that it is their problem and so the use of a router, although regrettable, will have to be the "fall back" solution to the problem.
Stripes may find it useful to be able to connect more than one machine from time to time and some people are happier leaving a router on 24/7 and being able to turn off their computer. Personally, I just let my Macs go to sleep- and I will now try to do the same
