Motorola modem SB6120 not identifying gigabit router (ASUS RT-AC66U)

[Drig]

Just got this router a week ago and noticed Link light on the modem is changing from blue to amber, reset router get it back blue then same thing.
Tried different cables still same thing, any thoughts?

 

[Marinemaster]

Power off router, power off cable modem. Wait 2 minutes. Power on cable modem. Wait it 5 minutes. Power on router. Wait it 5 minutes. Login to the router.

 

[RMerlin]

No idea what that led is for, but in case it would be to tell you what's the Ethernet link speed, make sure the cable you use between the modem and the router is labelled Cat5e or higher. Older Cat5 cables cannot be reliably used with Gigabit interfaces.

 

[Drig]

No idea what that led is for, but in case it would be to tell you what's the Ethernet link speed, make sure the cable you use between the modem and the router is labelled Cat5e or higher. Older Cat5 cables cannot be reliably used with Gigabit interfaces.

Yes its for Link speed-Blue is 1000mbps
Wasn't using the cable that came with the router was using longer cat 5e
tried a couple I had, but was causing problems turning amber 100mbps
went to the stock cable that came with the router solid blue now!

 

[RMerlin]

Yes its for Link speed-Blue is 1000mbps
Wasn't using the cable that came with the router was using longer cat 5e
tried a couple I had, but was causing problems turning amber 100mbps
went to the stock cable that came with the router solid blue now!

I read a few reports about the difficulty of getting a reliable Gigabit link with these modems. Suspecting it might be a FW issue with that modem model, or something related to the switch it uses.

I have a Thompson DCM475 here, works great for me.

 

[PrivateJoker]

I read a few reports about the difficulty of getting a reliable Gigabit link with these modems. Suspecting it might be a FW issue with that modem model, or something related to the switch it uses.

I have a Thompson DCM475 here, works great for me.

That was a pretty good call by Merlin, I absolutely hate LEDs that will illuminate different colors to show anything other than yes/no. . .Sony likes me to remember what solid & blinking: green; amber; and red mean on the link light on its Airplay speakers

To the OP, I'd say definitely swap out your modem if it's flaky and under warranty or lease, you should have a fully functional unit for sure, but unless you have extremely fast internet service you probably won't ever saturate a 100Mb/s WAN connection.

 

[Drig]

I read a few reports about the difficulty of getting a reliable Gigabit link with these modems. Suspecting it might be a FW issue with that modem model, or something related to the switch it uses.

I have a Thompson DCM475 here, works great for me.

Guess I spoke to soon back to amber!
Had the dlink dgl4500 to this modem for a couple years always blue

 

[TonyH]

Yes its for Link speed-Blue is 1000mbps
Wasn't using the cable that came with the router was using longer cat 5e
tried a couple I had, but was causing problems turning amber 100mbps
went to the stock cable that came with the router solid blue now!

Hi,
Blue means it is capable of 1Gb speed not it is runnnig at that speed. I wonder
what was the reason OP did not try enclosed cable first???

 

[PrivateJoker]

Hi,
Blue means it is capable of 1Gb speed not it is runnnig at that speed. I wonder
what was the reason OP did not try enclosed cable first???

Personally I try to use as few of the cables that come in consumer electronics as possible (granted, I also have a massive cable stash that some might say borders on hoarding) for purposes of leaving as much of the box and its original contents in shape for possible return and/or eventual resale on eBay.

 

[Marinemaster]

Did the same cable worked correctly before ?

 

[Drig]

Hi,
Blue means it is capable of 1Gb speed not it is runnnig at that speed. I wonder
what was the reason OP did not try enclosed cable first???

I just used the cat 5e cable that was from the other router that was replaced

Personally I try to use as few of the cables that come in consumer electronics as possible (granted, I also have a massive cable stash that some might say borders on hoarding) for purposes of leaving as much of the box and its original contents in shape for possible return and/or eventual resale on eBay.

I agree, I do the same

Did the same cable worked correctly before ?

Yes, every cable has worked blinking blue but then eventually goes blinking amber.
Had Comcast technical support reboot the modem on there end, back to blue right after.

 

[F5ing]

Just got this router a week ago and noticed Link light on the modem is changing from blue to amber, reset router get it back blue then same thing.
Tried different cables still same thing, any thoughts?

I've had this same modem for a few years. Link LED typically blinks blue (if all is normal). I'm guessing this is what you're used to seeing, right?

Have you tried resetting the modem back to factory defaults (the button is available on the modem's Configuration page)?

 

[Drig]

I've had this same modem for a few years. Link LED typically blinks blue (if all is normal). I'm guessing this is what you're used to seeing, right?


Have you tried resetting the modem back to factory defaults (the button is available on the modem's Configuration page)?

Correct always blue. Glad someone else has one to compare.

haven't tried that yet but I thought about It, been blue since Comcast restarted it on there end so far. If it changes I'll set it to factory good idea thx
Never had an issue, bought this new router started seeing amber light! just not sure if its the router?

 

[PrivateJoker]

Correct always blue. Glad someone else has one to compare.

haven't tried that yet but I thought about It, been blue since Comcast restarted it on there end so far. If it changes I'll set it to factory good idea thx
Never had an issue, bought this new router started seeing amber light! just not sure if its the router?

@Drig, it's been awhile since I've owned a Motorola cable modem, but I wouldn't be surprised if you had a similar page with similar details for you at whatever your gateway's address is. Here's a pic of my Arris confirming its gigabit connection.

Then also at the bottom of this page on my RT-N66 it will confirm the WAN connection speed.

http://192.168.1.1/Tools_Sysinfo.asp

hth!

 

[Drig]

@Drig, it's been awhile since I've owned a Motorola cable modem, but I wouldn't be surprised if you had a similar page with similar details for you at whatever your gateway's address is. Here's a pic of my Arris confirming its gigabit connection.

Then also at the bottom of this page on my RT-N66 it will confirm the WAN connection speed.

http://192.168.1.1/Tools_Sysinfo.asp

hth!

Not near as detailed as yours

 

[PrivateJoker]

Not near as detailed as yours

Dang! "modem status operational" - ha. I'm assuming no further helpful info hiding under the other tabs (if it even lets you peek at them)?

 

[Drig]

Nothing at all under other tabs that would be of help

 

[PrivateJoker]

Nothing at all under other tabs that would be of help

Oh well...I guess get it swapped out (or for alternate model) assuming it's still under warranty.

But at the same time, unless the bandwidth you're paying for is over 100Mb/s, that connection not being gigabit probably isn't holding your network's WAN performance down.

I suppose I could test this by plugging my workstation directly into modem using both its gigabit & fast Ethernet ports and trying speed tests.

Also, if you're trying to figure out if its the modem or the router - I believe you could plug any gigabit hardwired device you have (laptop, desktop, another router) and at least as I sit here and try with two routers that have gigabit switches (but are not Asus) and not hooked up to anything else, I believe the ports can agree on a speed, and will indicate, even without any data flowing or proper router settings. I can plug a/v equipment (that is fast ethernet) into a Linksys router I have here and get a blue LED on the linksys, but connecting my laptop to any port (including WAN) will illuminate it in green.

 

[Drig]

Oh well...I guess get it swapped out (or for alternate model) assuming it's still under warranty.

But at the same time, unless the bandwidth you're paying for is over 100Mb/s, that connection not being gigabit probably isn't holding your network's WAN performance down.

I suppose I could test this by plugging my workstation directly into modem using both its gigabit & fast Ethernet ports and trying speed tests.

Also, if you're trying to figure out if its the modem or the router - I believe you could plug any gigabit hardwired device you have (laptop, desktop, another router) and at least as I sit here and try with two routers that have gigabit switches (but are not Asus) and not hooked up to anything else, I believe the ports can agree on a speed, and will indicate, even without any data flowing or proper router settings. I can plug a/v equipment (that is fast ethernet) into a Linksys router I have here and get a blue LED on the linksys, but connecting my laptop to any port (including WAN) will illuminate it in green.

Thought of plugging the dlink dgl4500 that I'm using now as an access point back in for a while to see if it would change, but since Comcast set the signal to it yesterday its been blue and hasn't changed yet.
speeds are 100mb/s down-20mb/s up

 

[PrivateJoker]

Thought of plugging the dlink dgl4500 that I'm using now as an access point back in for a while to see if it would change, but since Comcast set the signal to it yesterday its been blue and hasn't changed yet.
speeds are 100mb/s down-20mb/s up

Cool, maybe try that if it craps out again.

And theoretically fast Ethernet is capable of doing 100Mb/s full duplex, both directions, and also real world you probably won't see 100/20 connection to anything other than the closest possible speed test server. So, noticeable impact might be nothing other than LED display behavior, but yes it'd bug me too.