How to use Cisco C9500 25GE ports in 1GE mode

[COLIN]

Hi

Please could someone tell me how to configure a C9500 switch interface that is named Twentyfivegige as a 1G mode uplink to a ISR 4351 router. media type is fibre therefore is it just a case of using a 1G SFP or is configuration requiered on the interface ?

Many thanks

Colin

[pman · Accepted solution]

Hi,

for the C9500 There is no specific configuration you need to do,
Just insert the SFP and verify the link speed using the show interface command

You should see a line similar to the following on the C9500 :
Full-duplex, 1000MB/s, link type is auto, media type is 1000BaseSX SFP

[Jitendra Kumar · Accepted solution]

ISR 4351 router should auto-negotiate with Switch insert SFP and check show interface x/x.\

This dual mode port can only be used as either copper of SFP at any given time, not both. Because of this, the ISR 4331 has a maximum of 3 usable 1G interfaces, even though 4 are physically present on the unit.