cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements

Cisco announces new innovations in SD-WAN, ISRs, SD-WAN Services, and Catalyst 9000 Series switches


63
Views
0
Helpful
1
Replies
Highlighted
Beginner

Networl physical loop and no keepalive command

Hi,

 

I recently I had a network problem where I lost connectivity with one of our branch offices. After some troubleshooting I found out that the problem was due to a network loop. Someone had connected an IP phone to two different network sockets on the wall. There weren't any log error messages on the switch and I was wondering if it is due to the lack of the "no keepalive" command issued on the switch ports. If I had issued the no keepalive Would I have got an error message showing that there was a loop?

 

Thanks in advance.

1 REPLY
Enthusiast

Re: Networl physical loop and no keepalive command

Please verify that you are using Loop guard. Loop guard will automatically detect a loop and shut the ports down.

 

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/layer2/configuration_guide/b_lay2_152ex_2960-x_cg/b_lay2_152ex_2960-x_cg_chapter_01000.html#ID756

 

You would not have seen a log if you had the keep alives enabled.

 

Please mark helpful posts.

CreatePlease to create content
Content for Community-Ad
Ask the Expert- DMVPN on Cisco routers