Another Case of RBR50 with Spectrum MODEM

[EdwardMac]

Orbi RBR50 SN 5VG1935K08580

Firmware v2.7.5.6

Router works fine with Brightspeed vDLS2 MODEM and with Starlink V3 MODEM.  

Connected today to Spectrum 1G Cable Internet service.  Tried to plug directly into Spectrum Cable MODEM

Spectrum Model EU2251 DOCSIS 3.1 eMTA

I noticed that the only output port of the Cable MODEM is marked 2.5G. 

Other MODEMs have 1G ethernet outputs.

I connected the Spectrum Wifi Router (with built in ethernet switch) to the Spectrum DOCSIS MODEM and then connected the Orbi RBR50 to one of the 1G ethernet ports on the back of the Spectrum Wifi Router.  It works fine that way.

I would think that a 2.5G ethernet switch should be backward compatible to 1G ethernet.  But in case I'm wrong: can the RBR50 connect to a 2.5G ethernet port?

Thanks for your help.

[CrimpOn]

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@EdwardMac wrote:

I would think that a 2.5G ethernet switch should be backward compatible to 1G ethernet.  But in case I'm wrong: can the RBR50 connect to a 2.5G ethernet port?

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Yes, 2.5, 5, and 10G Ethernet ports are generally backward compatible with 1GB.

Should connect just fine.

[EdwardMac]

Thank you.
May I ask you your opinion on the failure? Since the RBR50 doesn’t work with the Spectrum MODEM 2.5G port, is it safe to say that the problem is the Spectrum MODEM?

[CrimpOn]

Spectrum documentation clearly states this modem supports multiple Ethernet speeds:

The typical procedure is to:

• power off the modem
• connect the customer router WAN port (often Yellow) to the modem Ethernet port
• power up the modem and wait until the lights stabilize
• power up the customer router