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CM400 suddenly very slow

JK-VA
Guide

CM400 suddenly very slow

Xfinity cable internet. Paying for 100 mbs. Usually getting 100-115. Last 36h suddenly dropped to 9 mbs. CM400 5y old. Of course Xfinity says nothing wrong on their end. Delivering appropriate speed. Typical response of must be old modem and needs replaced. Happened one other time about 1y ago and it was a setting on their end. Have reset modem and router with no change. Can anyone help me with checking the modem? See attachment
Message 1 of 10
plemans
Guru

Re: CM400 suddenly very slow

I didn't see an atachement. 

do you have a screen snip of the cable connections page and the modem logs?

Those help check the signal. xfinity is notorious for their first response being "its not the line"

You can click on "choose file" and add them that route so we can see them right away. Otherwise a moderator has to approve them. 

 

Also, if you have any cable splitters, attenuators, amplifiers in the coax line, remove them.

Check the line for kinks, bends, damage, loose/old/bad connections

 

Current setup: CM2000-> RBKE963B-> Trendnet TEG-S380-> GS716T-> pi-hole
1.4gig download/50mbps upload
We’re members of the public helping out on our own time.
Message 2 of 10
JK-VA
Guide

Re: CM400 suddenly very slow

Sorry I did choose file. It just didn’t load.
Message 3 of 10
plemans
Guru

Re: CM400 suddenly very slow

Do you also have your logs?

You've got errors in the line. I'd check the line and remove any splitters, amplifiers, or attenuators. Check the line for kinks, damage, bad/cheap/old/loose connectors. 

Current setup: CM2000-> RBKE963B-> Trendnet TEG-S380-> GS716T-> pi-hole
1.4gig download/50mbps upload
We’re members of the public helping out on our own time.
Message 4 of 10
JK-VA
Guide

Re: CM400 suddenly very slow

Not sure how to get the logs.
Message 5 of 10
JK-VA
Guide

Re: CM400 suddenly very slow

Will have to post logs later when I get home. Thanks
Message 6 of 10
JK-VA
Guide

Re: CM400 suddenly very slow

Event logs
Message 7 of 10
plemans
Guru

Re: CM400 suddenly very slow

Did you just reboot it? You should have more than 2. Rub it for a bit (24-48 hours) and pull the logs back up
Current setup: CM2000-> RBKE963B-> Trendnet TEG-S380-> GS716T-> pi-hole
1.4gig download/50mbps upload
We’re members of the public helping out on our own time.
Message 8 of 10
JK-VA
Guide

Re: CM400 suddenly very slow

Yes last night 3x. Per Xfinity on line automated support, phone support, and Netgear support. They wouldn’t listen that I had already completed that task. The first level phone consultant had it as part of the algorithm and couldn’t think past it. Will post more in 48h. Thanks
Message 9 of 10
JK-VA
Guide

Re: CM400 suddenly very slow

So after over 48h, event log is unchanged. Speed is still 9 mbs. New modem? New router? Call Xfinity again?
Message 10 of 10
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