2821 - Ethernet interface bouncing?

chulke0000 · ‎01-07-2010

Hello, I'm not sure if this is the right place to ask a question like it, but I thought I would try...

I have a 2821 at a Colocation in a cabinet that my company is renting from a telco. Two times last month our internet connection went down there and what ultimetly brought us back online was physically unplugging us from the telco's switch and plugging it back in. The telco's tech tried to reboot/reset the switch port and even that didn't work, the only thing that fixed it was physically unplugging/replugging. Now the telco is blaming my equipment, saying that something with my router must be causing the problem with the switch port. During an outage I tried everything on my side that I could (rebooting router, unplugging/replugging on my side, etc) but as I said the only thing that fixed the problem is physical unplugging/replugging on the telco's switch. I checked out the log and during the outage it did show the interface as going up and down:

000130: *Dec 9 14:12:24.319 PCTime: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up
000131: *Dec 9 14:12:34.319 PCTime: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to down
000132: *Dec 9 14:13:04.319 PCTime: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up
000133: *Dec 9 14:13:14.319 PCTime: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to down
000134: *Dec 9 14:13:34.319 PCTime: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up
000135: *Dec 9 14:13:44.319 PCTime: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to down

The telco's techs are blaming my router and I'm wondering if it makes any sense that a router could mess up a switch port until it it physically unplugged? Is there any kind of diagnostics I can run on my router to prove that my equipment is good? Thanks!

cindy toy · ‎01-19-2010

Hi chulke0000,

The Small Business Support Community is limited to Cisco Small Business Products.

Your question below relates to a Cisco Classic Product which our community would not be able to help you with.

The best area for you to post your question would be at the Cisco NetPro forums: http://forums.cisco.com/eforum/servlet/NetProf?page=main

Best regards,

Cindy

Cindy Toy

Small Business Community Manager

Customer Advocacy

Cisco Systems, Inc.

Regards, Cindy If my response answered your question, please mark the response as answered. Thank you!

wichilds · ‎01-20-2010

chulke0000,

I do not know if the switch you are attaching to is a layer 3 switch/multi-layer switch so answering this question is a bit difficult. I do know that security issues (a port being authorized) will cause a switchport to go into errdisabled state, but that does not appear to be the case here. It looks as though a cable/connector or possibly the interface on one side or the other is/maybe going bad. It does not appear that a duplex mis-match, trunk negotiation, UDLD, etc. is causing this, therefore it looks to be the interface. If the interface is on a card, try replacing the card. If not the next step may be getting TAC involved.

Bill