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Testing Cable TDR.. getting shorts on pair c and d

joshhboss
Level 1
Level 1

So I am just getting my feet wet with cisco switches.. and i was really excited about being able to test cables with the TDR function.. but i have noticed that when i test the cables with IP cameras (always negotiate at 10/100) the test shows a fail on pair c and d.. Is there anyway to get the test to show just if the pair is good.? i tried to force the negotiation at 1000 but it still shows me the shorts on c and d.. is this something i will not be able to get around because the camera does not have the ability to go 1gig.. 

 

using cisco 2960s POE 24 port and 48

 

Thank you 

4 Replies 4

Cristian Matei
VIP Alumni
VIP Alumni

Hi,

 

    Pairs C and D are only tested for GiagbitEthernet links, so there's nothing you can do, except using a Gig port. See more reference about TDR here:

 

https://community.cisco.com/t5/networking-documents/how-to-use-time-domain-reflectometer-tdr/ta-p/3119327

 

Regards,

Cristian Matei.

Hi,

 

They are gig ports.. just the cameras negotiate at 10/100.. i just figured the tdr was a function for testing the pairs.. :(.. i tried power inline never. and still reads shorts on pairs c and d.. and the cable is definitely good. 

 

:(!

Hi,

 

  It negotiated FastEthernet, so even though it's a physical Gig port and capable cable, it runs as FastEthernet, thus TDR does the same.

 

Regards,

Cristian Matei.

Martin L
VIP
VIP

short/short is ok for gig ports when speed is not 1 gig; results are ok if they show
normal
normal
short
short
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