Airport Extreme Not Identified as Gigabit on SB6141

[keithp]

Just installed a new Motorola SB6141 Cable Modem (white retail version) to work with an Apple Airport Extreme and a Mac Mini. Connections and speeds are fine using Comcast 50 Mb service.

I connected the Cable Modem to the Apple Mac Mini, and completed the Comcast online configuration process.

The Cable Modem's LED 5 flashed blue, indicating the Mac Mini was operating in high-speed Gigabit Ethernet mode.

Speedtest.net showed 54+ Mbps.

I connected the Cable Modem to the Airport Extreme via it's Ethernet WAN port, and the Mac Mini to the Airport Extreme via one of it's 3 Ethernet ports.

I unplugged both the Cable Modem and Airport Extreme, restarted the Airport Extreme, and then restarted the Cable Modem.

Now the Cable Modem's LED 5 flashes amber, indicating the Airport Extreme is operating in Fast Ethernet 100Base-T mode.

Speedtest.net shows 54+ Mbps.

I've since switched back and forth a couple of times. When the Mac Mini is connected directly, the Cable Modem flashes blue, and when the Airport Extreme is connected directly, the Cable Modem flashes amber.

The Airport Extreme's WAN and Ethernet ports are specified as Gigabit Ethernet. The Mac Mini's Ethernet ports are specified as Gigabit Ethernet.

Can anyone explain this behavior of the Cable Modem indicating different Ethernet modes?

Thanks in advance.

 

[thetoad30]

What is the spec of the cable between the Extreme and the modem?

If you use that same cable from your computer to the modem, or from the Extreme to the computer, what is your link speed?

It sounds like a handshake issue to me - if you have another CAT5e or higher cable to test, I'd try it.

I understand why you want it to work, since I would as well, but do note that the link will not affect your internet speed at all since you are well below 100mbit one-way. In fact, with that service (I have it too) you should get a max of say 65 up and 15 down, making your throughput a total of 80mbits/s.

 

[keithp]

What is the spec of the cable between the Extreme and the modem?

Thanks for your feedback. I used the same cable for the two connection tests. It's the CAT5e cable that came with the SB6141.

I realize it's not affecting the performance of my 50Mb service, but it does fall into the Annoying Category. And there's part of me that just wants to know why it's happening.

I've got two ideas that I've not tried yet:

1) Restore the Airport Extreme to it's factory default while connected to the Cable Modem. Then power down and power up the Cable Modem.

2) Restore the Cable Modem to it's factory default and power it down. Connect the Cable Modem to the Airport Extreme, power the Cable Modem up, and go through the Comcast configuration process. (The first time I went through the Comcast configuration process, the Cable Modem was connected to the Mac Mini.)

Do you think either of those would result in a different handshake, and the Airport Extreme being recognized as a Gigabit device?

 

[Wangta]

Thanks for your feedback. I used the same cable for the two connection tests. It's the CAT5e cable that came with the SB6141.

I realize it's not affecting the performance of my 50Mb service, but it does fall into the Annoying Category. And there's part of me that just wants to know why it's happening.

I've got two ideas that I've not tried yet:

1) Restore the Airport Extreme to it's factory default while connected to the Cable Modem. Then power down and power up the Cable Modem.

2) Restore the Cable Modem to it's factory default and power it down. Connect the Cable Modem to the Airport Extreme, power the Cable Modem up, and go through the Comcast configuration process. (The first time I went through the Comcast configuration process, the Cable Modem was connected to the Mac Mini.)

Do you think either of those would result in a different handshake, and the Airport Extreme being recognized as a Gigabit device?

Keith - were you able to resolve this? I just got the Motorola SB6141 and ASUS RT-N56U for Comcast 50/10 package. Everthing seems fine, except my LINK light is constantly blinking amber.

I bought a new cat5e cable, tried the cable that came with the Motorola SB6141 modem, used the cable that came with the router - ALL result in Amber blinky.

!???

Curious, what speeds are you getting?

I did a couple speedtests and I'm getting 21 up and 10.5 down. Wondering why my down is so low???

 

[FrancoisC]

Same modem here (my provider is Videotron) and had the same problem with a n66u an ac66u, if I reset the router a couple of time it connect at gigabit speed.

I made a small search, it seem to be common with this modem.

 

[sfx2000]

Check the patch cable - quick google search says that the one shipped with the Surfboard is less than optimal.

sfx

 

[FrancoisC]

In my case even a cat 6a cable didn't help.

Anyway, I got a different modem since then and everything connect at the right speed now.