Intermittent one-way packet loss
 

Exactly what it says on the tin :)

Every now and again, one of the buildings in my college (small college, one router in the main building, switches elsewhere with various media converters/laser links etc) will disconnect from the rest of the college for hours/minutes. It then goes back up for mins/hours, and repeats.

At first, I assumed that the building was disconnecting completely - during an episode I can ping computers in the same building, but not ones on the main college site. However, running a port capture recently showed me that the various broadcasts from the main site are reaching this building - but it seems packets are not going the other way.

The same hardware has been working absolutely fine for some time - the problem started this year; our computer officer is blaming a combination of WinXP and DHCP (why DHCP I completely fail to understand).

Does anyone have any ideas? I'll happily provide further info if I can... I have two 2 minute port captures, one from a period when it was working, and one when it wasn't...

Thanks!

spanning tree

I've found some entries in the logs that mention spanning tree (I know nothing about this BTW) - what should I be looking for? There are 3 MAC addresses broadcasting STP messages. The only obvious difference I can find between the two logs is that in the 'working' one, one of the MACs is sending "Conf. TC + Root" rather than "Conf. Root" Does that mean anything?

I'll have a look on google, but any other information would be gratefully received :)