Can't Connect to Anything Internet

[high_acidity]

dual 2.0 G5, rev. b, 3G ram
10.4.2
DSL modem/4-port switch

I cannot connect to anything online...

I can print to my networked printer (printer connected to same switch as Mac), I can see this G4 iMac on the G5 (again, connected to same switch), but I cannot get both Safari and Firefox to load a page (get the "you are not connected to the internet" message), no email, or any other app that requires internet connectiveness.

As far as I know, I have not changed anything on the G5, and I have been smoothly running 10.4.2 with everything currently updated for a while. Have not installed any new apps either.

I have done the following to troubleshoot:
- Rebooted modem/switch (many times)
- Repaired permissions, preferences, etc. using AppleJack in deep clean mode (several times)
- Repaired the disk with Disk Utility (booted from Tiger install DVD)
- Changed ethernet cable between G5 and switch twice, once using the same cable that is working right now on this iMac
- Reinstalled 10.4 from DVD, did an Archive Install, installed updates to 10.4.2 (from copies of updater on hard drive)
- Removed all network and SystemConfiguration (folder) preferences from Library/Preferences, then re-set up my network in System Preferences
- Unplugged all USB devices except for keyboard/mouse

No change... then I booted from my cloned backup on a firewire drive that had 10.3 on it... still no go! That floored me.

It seems like a software problem, but then why can't I get online from the backup?

Help please... thanks so much.

 

[barhar]

Unknown information:
DSL modem - model and manufacturer.
4 Port switch - model and manufacturer.

Assuming the DSL modem does not have an internal router; and, assuming the 4 port switch is indeed a switch, and not a router - replace the switch with a multiple port router.

 

[high_acidity]

The DSL modem (it says router on the model label) and 4-port switch are one unit... the ZyXEL Prestige 643.

Things are "mysteriously" working on this machine now after not booting the G5 for a day... and the last two days have seen our other machines lose their ethernet connections for periods of time, a Mac Mini and an IBM Thinkpad. Both have their connections just fine now.

So the common denominator is now the Zyxel unit. Do these devices fail often, and would it be an intermittent thing like this?

 

[Hainzy262]

What Ip address do u get on the mac? 10.x.x.x 169.x.x.x 192.x.x.x or 8x.x.x.x.
also what does your printer have.
Also check if u have file sharing on. use Network Manger to ping 127.0.0.1 (your ethernet port) also enter 17.254.3.183 in to web browser to see if you have a dns problem.