Massive network disconnection

As reported from the MIU mailing list:

Dear all,

Sorry for the not so good news. Early Friday (Jan 19), internet users of UPCM experienced an erratic connection to permanent disconnection of PC's in the network. Upon checking the possible points of network failure (dagohoy, main switch in SPADE, switches) and consulting Jay of IMS, here are the findings:

1. The UPCM segment was disconnected automatically due to a series of warnings and error messages in the core switch according to Jay. He later enabled the connection for us to find out the cause of the problem

2. We checked the main switch in SPADE. A laptop was connected to the 24-port switch. Just like the other machines in CM, the machine was able to get a 169.xxx.xx.xx IP address.

3. The converter in the SPADE main switch should have three blinking lights (power, fiber optic, LAN). The lan cable (straight) was disconnected from the switch and connected in a laptop. The LAN bulb went off. Jay suggests to use a crossover cable instead. When the crossover cable was re-connected to the laptop, the LAN bulb lights up but the machine still gets a 169.xxx.xx.xx IP address.

4. To check if there is a problem with the switch, we disconnected the uplink cable from the converter and replaced it with a MyDSL line in Dr. Balgos' office. All LAN cable were removed except the one connected to the laptop. The laptop was able to get an IP from the MyDSL router and can connect to the Internet. This might mean that there is no problem with the switch.

5. As of now, the main suspect is the media converter (the one we borrowed from IMS). We hope to test another converter but we don't have any available supply as of this time. Jay also mentioned the possibility of some desktops that causes network interruption due to virus.

The next action will be to test another converter just to make sure that this hardware is the cause of disconnection.