Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I'm having some weird troubles with our smb network. There isn't any documentation about the structure/devices or which cable is attached to which wall socked and I'm discovering lots of weird stuff. I've already removed 3 network loops and set up 3 of the 5 switches as managed and enabled STP but the weird behaviour still exists: All activity lights of all switches are flashing in exactly the same rate which makes me think there must be another loop or hub in the network. Another issue is that one of the new HP V1910 switches is logging the following exactly every 2 seconds (This makes me think of the STP hello timer interval):

Instance 0's port GigabitEthernet1/0/1 was notified of a topology change.

GE1/0/1 is connected to our backbone switch, which isn't managed. So I can't figure out what's going wrong. I also can't replace it (not new or temporarily).

What would be a good approach find the cause of these issues?

share|improve this question
Tracing/documenting every port/device should be the first order of business, and make sure to look for wireless access points / temp connections. Also I would sniff the traffic on that gig1/0/1 and see where / what is generating the spanning tree bpdus. –  Doon Feb 11 '13 at 12:15
The bpdus are coming from a device called "acctonte_xxxx" (according to wireshark). Accton is a brand of network devices, but I can't find any device of Accton. There is of course always a chance it's rebranded. –  user158470 Feb 11 '13 at 12:25
Documenting every port is almost impossible. There are switches connected to other switches laying under the floor, so 30 pc's may be connected to 1 port on the patch panel in the rack. Perhaps there is some tool that can draw a diagram of a network based on traceroutes/mac addresses? –  user158470 Feb 11 '13 at 12:32
Nothing is impossible given enough time (Or interns..). When you have switch to switch to switch, and no diagram etc you can spend hours trying to issue just at the network level. especially when not all the switches are managed. What type of Switches are they, or they a hodgepodge? how many PCS / Devices? Any wireless (accton make wireless stuff as well) –  Doon Feb 11 '13 at 12:39
I'm trying to avoid wasting hours. An overview: 60 clients (all macs), 2 HP V1910 managed switches, 2 3COM 2426-PWR Plus managed switches, 2 alcatel unmanaged switches, 5-10 no name cheap ass 8 port unmanaged switches and 2 cisco wireless access points –  user158470 Feb 11 '13 at 12:44

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.