Connecting 10x SFP-10G-SR-S to a 1G Interface

[zekebashi]

Hello,

I've an ISR4451-X router, which comes with 4x 1GE interfaces, and I want to connect it to a C4500-X switch, which comes with 16x 10G interfaces. I'm using SFP-10G-SR-S on the C4500 and want to know which SFP module I need to use on the ISR4451 to connect those devices together. 

Is it even possible to connect a router which has a 1GE to a switch which has a 10G-SR-S SFP? 

Thanks in advance. 

Best, ~zK 

[Marvin Rhoads · Accepted solution]

No - you need to use a setup like either:

1. GLC-T (copper 1 Gbps transceiver) at the 4500-X end into the regular Cat 5 copper interface on the router, or 

2. Something like the GLC-SX-MM (multimode fiber 1 Gbps transceiver) at both ends.

A 10G-SR-S SFP cannot connect to a 1 Gbps transceiver or interface of any kind. The 4500-X SFP ports are backward compatible and can accommodate 1 Gbps SFP transceivers.

[zekebashi]

Thank you, kindly! 

Best, ~zK 

[zekebashi]

Hi Marvi,

I used GLC-SX-MM on both ends of a C4500-X and ISR4451 but the link won't come up. I disabled the speed autoneg on both interfaces but, still, the link won't come up. Is there some sort of configuration that I need to do on the 10G interface of the C4500-X? 

Much appreciated. 

Best, ~zK