Cisco switch doesn't recognise device behind it

[toshiyoshida60]

Hi, I have a problem with my network. I have a Cisco C1000 16-port switch, and currently, there are Linksys SR216 switches in my network. I would like to replace these Linksys switches with the C1000 switches. I have migrated everything, and everything is working as it should, but I have an issue with a device that seems to be some kind of alarm central. When I plug it into the switch port, it doesn't respond; the interface is down and there are no logs whatsoever. However, when I plug it into a Linksys port, it starts working automatically. I've tried different models of the C1000 switch, but the problem remains the same.

Interestingly, I think I have noticed a pattern: when I use a switch with 10/100 ports, it works, but when I use a switch with 10/100/1000 ports, it doesn't. The configuration is quite simple: VLAN 1, everything is set to access, with one trunk to the router, and that's it.

If you have any ideas, I would appreciate your help in resolving this issue.

[marce1000]

        >... when I use a switch with 10/100 ports, it works, but when I use a switch with 10/100/1000 ports, it doesn't.
   - What speed does it use (negotiates) on a 10/100 switch ? Does it help to set that speed manually on a 10/100/1000
      switch, 

 M.

[balaji.bandi]

we have seen this kind of issues in the past, so try make it manually 10MB or 100MB depends on the device capabilities

try different options as below :

https://www.cisco.com/c/en/us/support/docs/lan-switching/ethernet/10561-3.html

[paul driver]

Hello
Have you tried hardcoding the interfaces speed/duplex ?

[amikat]

Hi,

Can you please try to configure "speed auto 10 100" under the interface your central alarm device is to be connected and check if there is any progress.

Best regards,

Antonin

[MHM Cisco World]

It L1 issue 

MHM