02-26-2008 08:04 PM - edited 03-05-2019 09:24 PM
Hi, I am currently trying to resolve a issue i have with 2, 3750's which are stacked together. I currently have 27 Cisco IP PoE Phones plugged in across both switches, (18 on Master, 9 on Slave) models are both 7940's and 7960's. However when I plug in a 28th phone, the network dies, all the PC's and phones (other than the one just plugged in) reset and lose their connections, and will not come back until the 28th phone is unplugged. However if i remove one phone, and then re-plug another phone in, everything is fine. Below are some tests that i performed to find out if it was a PoE issue on the switches.
When i say PoE was Disabled, i mean i had turned the power inline to never, and had the phone powered by the AC Adapter.
Had 27 phones plugged in, plugged in number 28 with PoE enabled = Network Dies
Had 27 phones plugged in, plugged in number 28 with PoE DISABLED = Network Dies
Had 26 phones plugged in, plugged in number 27 with PoE enabled = Network stays active
Had 26 phones plugged in, plugged in number 27 with PoE DISABLED = Network stays active
Also, when i issue the sh power inline command it tells me following:
Module Available Used Remaining
(Watts) (Watts) (Watts)
------ --------- -------- ---------
1 370.0 113.4 256.6
2 370.0 56.7 313.3
On the 3750's i am running C3750-IPSERVICESK9-M Version 12.2(25)SED1 IOS.
Any help is greatly appreciated, thanks for the help in advance.
Regards,
Robert N.
CCNA.
02-26-2008 09:50 PM
Bizarre. Turn the logging up to debugging and rerun those tests.
02-27-2008 01:58 PM
Ok, well this is another twist. Turned on logging and nothing to exciting turned up. Went to that office after hours to try and force the network down, however no matter how many phones i plugged in, nothing would happen (plugged in 6 phones, 7940's, 7960's 7912's)... So my thoughts are it may be the Gbit link we have from this office to our Co-Location, so i have set up some MRTG graphs to help try and find out if it is the link under intense strain.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide