I sat down at my computer this morning to finish my newsletter, only to find the hated words "Not connected."
Windows 7 was informing me that I had no network connection. Not just no Internet access, but not even access to the other computers on my home network. This was a horrible morning.
Everything worked fine last night when I went to bed. It was time to put on my Debugging Hat…
My first step was to reboot my Motorola SB6120 DOCSIS 3.0 cable modem and my router. The process was easy and seemed to be fine. Unplug the power to the cable modem; unplug the power to the router; plug in the power to the cable modem; wait for the cable modem to download it’s configuration data from the cable Internet service provider and stabilize it’s lights, plug in the power to my Cisco-Linksys E3000 Wireless-N Router so it can make its connection to the cable modem and to the other computers and the Gigabit Ethernet switch connected to it.
But, it didn’t solve the problem…
My next "debugging" step was to call my son to see if he had experienced any problems the previous night, or had made any wiring changes. He had been playing World of Warcraft when I went to bed. No hints from this, though, as he had not had any problems and had not made any changes to the router, modem, or network wiring.
Another dead end…
Now, it was getting interesting and I had an Ace up my sleeve — actually an Acer…
I pulled my Acer ultralight notebook out of my rolling carry bag.
I remembered that my router was a wireless router, as well as providing wired Gigabit Ethernet connections. I wondered if the wireless connection would work. I powered on the notebook and immediately got an 802.11n wireless connection. I could use Firefox to get to web sites, so that let me know that the router was at least working wirelessly.
Does it work with Ethernet cables? I plugged the notebook into an Ethernet cable coming from the second Gigabit switch — no luck.
So, I disconnected the cable from the switch and plugged it directly into the router. Voilá! A network connection and an Internet connection via the wired cable. Just to make sure, I turned off the notebook’s wireless card. Yes, I still have access to the Internet. Yea!
So, now I knew that the router was OK and the cable modem was OK. The problem was somewhere in the wired networking side of my home network.
I had tested the router by directly connecting my notebook using an Ethernet cable. It worked.
I had tested the second Gigabit Ethernet switch by directly connecting my notebook using an Ethernet cable. It did not work. That didn’t tell me that the switch was bad, but that the problem was either the switch or something between it and the router.
I unplugged and plugged all the cables to that Gigabit Ethernet switch. No change.
At that point, I intended to do the same thing at the first Gigabit Ethernet switch, to which the router and the second Gigabit Ethernet switch were connected. Since that was underneath my computer desk, I had postponed getting down on my stomach to check it.
When I did, though, I found that the first Gigabit Ethernet switch (the one between the router and second switch) was (a) plugged in and (b) had no lights of any kind lit. It’s dead, Jim.
I went through some more debugging just in case — I unplugged and reconnected all the cables to it. I unplugged the switch’s power connection and plugged it in again. I unplugged its transformer from the surge protector and plugged it in again. All to no avail. It was dead. Time for a new one.
Fortunately, the switch that went bad was the very first Gigabit Ethernet switch that I had purchased, bought when the prices started to drop, and shortly after Cisco bought Linksys. It wasn’t stackable and wanted to be laid flat, to take up the maximum space. Ugh.
I had been thinking about buying another Gigabit Ethernet switch as a spare. Obviously, I didn’t think seriously enough about that.
I disconnected everything from my remaining Gigabit Ethernet switch (a Cisco-Linksys EG008W 8-port Gigabit Ethernet switch) and moved it to replace the switch (a different type of Gigabit switch) that no longer worked. I plugged all the cables into it and almost everything was fine — a little more searching, and I found that there was one more cable I needed to connect.
Now, everything works except my old desktop. It won’t have a connection until my new switches get here.
I’ve ordered two new 8-port Gigabit Ethernet switches, both the Cisco SD2008T 8 Port Desktop 10/100/100 Gigabit Switch.
Why did I pick this one? I was intending to purchase two more of the EG008W models. But, when I started looking, I found that the SD2008T as part of Cisco’s Small Business line of products, and included a "product lifetime warranty."
I’ll replace the EG008W with one of the new ones. The other new one will be used where the EG008W was previously located. The EG008W will be moved to my home theater system, where it will serve my home theater PC and my Internet-capable Samsung BD-C5500 1080p Blu-ray Disc Player.
Why did it happen? Who knows? Everything worked fine last night; then, at some time during the night, the 8-port Gigabit router failed, taking down network access for everything connected to it, including another Gigabit router, two networked printers (one black & white and one color), and multiple computers.