Tuesday, September 20, 2011

Networking Fun

The Cisco Linksys E1200 lasted five days...then stopped working on the WAN side.  My ISP came out, looked over the configuration, and finally decided that the Cisco router was bad.  It was flashing its little heart out on the WAN LED, but it could no longer hear the packets coming in on the WAN side.  They had a spare D-Link router in the truck, so that's what I am using now.

The only good thing about all this is how painless Amazon makes it to return defective products.  It asks you a couple of questions, and prints out a return postage paid form for the box.  This is as good as it gets, I suppose.

On an unrelated network issue--I noticed that the Intel PRO/100 VE Ethernet port on my HP DV5100 refuses to do anything better than 10 Mbps.  I thought that the problem was a 10BaseT cable.  No.  I can take the same cable and plug it into another HP laptop, and it is doing 100 Mbps over the same cable to the same router.  I can see the Intel PRO/100 VE port start out at 100 Mbps, then claim that the network cable is disconnected, and switch back down to 10 Mbps.  I have run Repair (which clears all the various local networking information), I have downloaded the latest version of the drivers from HP and Intel (and of course, these are several years old by now).  No luck.

It isn't exactly critical; the wireless card gives me 54 Mbps.  Still, it is a bit weird that this port or perhaps port and driver combination under Windows XP Pro can't stay at 100 Mbps.  I have searched extensively for others having this same problem, without success.


  1. Is there a way to hard-code the speed & duplex on the router/switch you're plugged into AND the NIC on the DV5100? If you can, hard code them both to 100MB/Full duplex and see if that fixes it. Sometimes the auto-negotiate for speed/duplex doesn't auto-negotiate so well.

  2. Try a different cable anyway; it might be that it's marginal enough that one PHY/driver combo can get 100, but the one in the laptop can't cope.

    (Monoprice has cables so cheap there's *no excuse* to not be using Cat-6 anymore.)

  3. I tried several different cables, and one cable that worked fine on another PC hooked to the same router port would not work here.

    You can hard code the speed and mode on the PC side, but I could not see an obvious way to do that from the D-Link configuration web. In any case, it manages to do 100 to other PCs without any difficulty at all.