pipermalibu
Registered
I thought I would post this unusual problem and solution to get it out in the ETHER net.
I have new house that the rocket scientist that built it put in ONE cat5 cable to each outlet in the house. This was for phone AND ethernet. No problem really, because 10/100 ethernet requires only 4 wires and my phone system also only requires 4 wires. It just means I cannot run 1000 ethernet (Gigabit). Everything is fine until I install a previously purchased (before I knew of the installers snafoo) Linksys gigbit switch. I plug it in and move the connections from a smaller 5 port switch (needed 10 ports) while the network is live. Done that for 20 years with no problems in work environments. Well my dual 2.5 powermac suddenly has no ethernet. Somehow I assumed that the port blew out with the switch. After installing a new ethernet PCI card (Dlink does not work, Netgear does) - I still have no network to the Powermac. I notice the lights on the card come on the card briefly at boot but then shut out a few seconds later. Hmmm, after some more testing, I discover that since the switch is Gigabit and the powermac is Gigabit, they are sending some sort of packet info over the 4 wires and can't figure out to backstep to 100Mb connection. The four wires confuse it. So I moved the Powermac to the routers 10/100 port and remove the ethernet card that was not needed and everything works great.
Moral of the story: Gigabit to Gigabit devices get confused and won't down step to 10/100 if only a four wire ethernet cable gets used. However, Gigabit to 100/10 devices still work fine with a four wire installation.
I am aware that this scenario may be unusual, but hopefully someone else will not spend a day trying to diagnose the problem when googling for an answer to the problem.
I have new house that the rocket scientist that built it put in ONE cat5 cable to each outlet in the house. This was for phone AND ethernet. No problem really, because 10/100 ethernet requires only 4 wires and my phone system also only requires 4 wires. It just means I cannot run 1000 ethernet (Gigabit). Everything is fine until I install a previously purchased (before I knew of the installers snafoo) Linksys gigbit switch. I plug it in and move the connections from a smaller 5 port switch (needed 10 ports) while the network is live. Done that for 20 years with no problems in work environments. Well my dual 2.5 powermac suddenly has no ethernet. Somehow I assumed that the port blew out with the switch. After installing a new ethernet PCI card (Dlink does not work, Netgear does) - I still have no network to the Powermac. I notice the lights on the card come on the card briefly at boot but then shut out a few seconds later. Hmmm, after some more testing, I discover that since the switch is Gigabit and the powermac is Gigabit, they are sending some sort of packet info over the 4 wires and can't figure out to backstep to 100Mb connection. The four wires confuse it. So I moved the Powermac to the routers 10/100 port and remove the ethernet card that was not needed and everything works great.
Moral of the story: Gigabit to Gigabit devices get confused and won't down step to 10/100 if only a four wire ethernet cable gets used. However, Gigabit to 100/10 devices still work fine with a four wire installation.
I am aware that this scenario may be unusual, but hopefully someone else will not spend a day trying to diagnose the problem when googling for an answer to the problem.