Networking problems G4-G5 linked via ethernet, G5 to router

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Level 3

685 points

Networking problems G4-G5 linked via ethernet, G5 to router

Hi

I have been having some REALLY odd networking issues recently. I will do my best to explain them as clearly as I can, and hopefully someone can make sense out of this mess.

I have a PowerBook G4, an HP laptop, and a Gateway PC connected to a Linksys wireless-g router via wireless-g. There is a gigabit ethernet hub connected to the Linksys wireless-g router. On this gigabit hub, cable runs to my Power Mac G5. This goes into the Ethernet 1 port of the G5. Out of the Ethernet 2 port goes a cable to my PowerMac G4. (Sometimes I hook the powerbook to the gigabit hub for fast transfer between it and the G5)

I can always connect to the PowerBook from the G5 for sharing and printing and vice-versa. I can never connect from the PowerBook to the G4 and vice-versa. iTunes sharing does not work with Powerbook to G4 either.

iTunes sharing used to work between G5 and G4, but just today I got a firewall message saying it could not connect.

While it is not the first time, I cannot connect from the G5 to the G4 via network. It had tried to connect with the weird FTP access dialogue box, so I restarted the G4, and now i get the "fix alias" number when I try to connect to the G4 from the G5.

Keeping that in mind, I can connect from the G4 to the G5 via Network perfectly fine. iTunes sharing on the G4 works too: I can see my G5's library.

Now, what is the problem with the G4? How come I can't connect from the G5?

Thanks,
Bret

G5 Dual Core 2.3GHz, MDD dual 867mhz G4; 15 Alum PB G4, 1.5GHz, Mac OS X (10.4.3), 2.5 GB; 1.75 GB; 1 GB RAM, respectively

Posted on Jun 21, 2006 6:49 PM

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Answer 1

etresoft

Level 9

57,554 points

Jun 22, 2006 8:45 AM in response to Bret Waters

This goes into the Ethernet 1 port of the G5. Out of the Ethernet 2 port goes a cable to my PowerMac G4.

Do I understand correctly? The G5 has two network ports. One port is connected to the gigabit hub and the other is connected to a PowerMac G4.

Please clarify with a exact list of port and connections like:
gigabit hub <-> linksys wifi
gigabit hub <-> PM G5
linksys wifi <-> PB G4
linksys wifi <-> HP
linksys wifi <-> Gateway

Where exactly does that PM G4 live? It should be connected to the hub like the PM G5. Then, your next step would be to ping each machine from every other one and see where things are screwed up.

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Answer 2

Bret Waters Author

Level 3

685 points

Jun 22, 2006 1:58 PM in response to etresoft

Do I understand correctly? The G5 has two network
ports. One port is connected to the gigabit hub and
the other is connected to a PowerMac G4.

Yes, you understand correctly.

gigabit hub <ethernet cable cat5> linksys wifi
gigabit hub <ethernet cable cat6> PM G5
linksys wifi <built in airport extreme> PB G4
linksys wifi <built in ?centrino?> HP
linksys wifi <linsys USB adapter>

The G5 and G4 are right next to each other in my basement. A 100 ft cable runs from the gigabit router to the G5. Instead of running another cable from the router to the G4 or having to purhcase another router I gave this a shot, as it took advantage of the G5's dual ethernet port capabilities and Mac OSX's internet sharing capabilities. It worked great for the last 4 or 5 months or so.

I dont know much about networking...pinging each machine is done how?

Thanks for the help.
Bret

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Answer 3

etresoft

Level 9

57,554 points

Jun 22, 2006 6:11 PM in response to Bret Waters

Aha! Well, I'm no expert on TCP/IP routing, so there isn't too much help I can provide. Your network is going to be quite sensitive to any changes. For example (and keep in mind that I don't know what I'm talking about), something as simple as your cable modem renewing its lease could cause your setup to break. In theory, it should all work - and it did for quite a while. But is has proven to be fragile.

At least I can help with ping. Get the IP address of each machine on your network. In the terminal, type "ping <ip address>". You can also use Network Utility, but that is more of a hassle for this kind of thing. You are well within "terminal required" territory. You want to build yourself a little map (and drawing it on paper is a good idea) of which machines can talk to which other machines. Also ping with some IP address on the Internet.

At some point, you will identify those connections that don't work. Then, try "traceroute <ip address>" to see what it is trying to do. Hopefully that will shed some light on things.

Check on versiontracker.com for a network mapping utility. There have got to be some free linux ones that will work on a Mac too. I would also suggest turning off every device on your network and then turning them all back on, one by one. The last one should be the leaf hanging off the other end of the G5.

Good luck. Years ago I had a similar setup routing my Internet connection through an old 7200 running LinuxPPC. I would reboot everything and all the machines could connect to anything on the Internet but were blind to the local network. Then, without changing anything, I would reboot and it would all work. Hardware routers always do this kind of thing better than CPUs.

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