The type of cable needed is certainly a Cross-Over cable. The error message you are getting in the G3 results from it not being able to "see" an active ethernet connect on the cable. The G4 must be running AND AppleTalk must be set to active. You get to that on the Network preference pane, click the AppleTalk tab and make it active.
Turn on File Sharing as well. The Firewall for the G4 is also in the Network prefs pane. Turn it off for this exercies.
On the G3, go to the AppleTalk control panel and select Ethernet as the transport for AppleTalk. If you continue to get the error, make sure the cable is a real cross-over OR connect the two machines together with a hub or a switch. You will need regular straight ethernet cable for this.
If the error continues, make sure you have the Apple ethernet extensions installed. Apple Enet and anything that sounds vaguely ethernet(ish). Check for this before the Hub or switch move.
If all appears to be there, you may have a defective ethernet chip. Farallon make a PCI ethernet card that will work for the G3 using OS 9
Good Luck
P
Im tying to connect a G4 I just bought (used) with my beige G3 through ethernet, using crossover cable.G4 is OSX and G3 is 9.2. Can't get appletalk control in G3 to go to ethernet, error message keeps coming up saying check connection. I have 2 drivers Ethernet(built-in) 2.4 and 2.01something. (computers are at work). Can these be the problem? Is it an extension problem? Should it be a straight connection cable? I really need this for work and would appreciate any help. If someone can guide me through it.
I read another post from 3/10/05 about a G3 and mini but still not there. Am not clear on the firewall thing mentioned, I don't know if I have one, my G3 isn't even a tower, its old.
Thanks, Mark

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