New Member
Posts: 6
Registered: ‎09-23-2014

Edgerouter Lite Random Slow Download Speeds, upload fine.

[ Edited ]

Edgerouter Lite Random Slow Download Speeds, upload fine.

 

I am having this same issue in the below link, and as a result an XKCD momment. (https://xkcd.com/979/):

https://community.ubnt.com/t5/EdgeMAX/Edge-router-Lite-Random-Slow-Download-Speeds/m-p/1518168#M1041...

 

Edit: (Maybe this is connected?)

https://community.ubnt.com/t5/EdgeMAX/Setting-port-to-100-Full-Duplex/td-p/1133395

 

I don't see a spoiler tag, so I will post my unit's config on pastebin. 

https://pastebin.com/r5qg8XK7

 

It seems they are having issues with forum post editor?

https://community.ubnt.com/t5/About-the-Ubiquiti-Community/Message-editor-change-intentional/m-p/219...

 

Unit: 

ER-Lite3

Software:

v1.9.7+hotfix.4  (It's been software updated multiple times over the last 2 years)

Setup:

Simple office network.  24 port, dumb, Gb cisco switch, comcast business modem, ER-lite

ETH0 is the internet, ETH1 is the port to the switch.

Internet:

Advertised speed: 100Mb/20Mb.  Comcast Business

 

 

Symptom:

Randomly, once or twice a month, the network devices on the inside of the network cruise at 10Mbps download,

and the normal 22Mb upload.  These were checked via speedtest to comcast and speedtest.net servers. Normal

speed is about 120Mb/22Mb.

 

>Plugging into the modem directly will usually restore full download speed to a single device.

>Rebooting all network devices won't always fix it.

>No major usage as reported in the ER-lite3 bandwidth usage graph, or CPU usage during this event.

>Tried two models from comcast, and one SB6183.

>Comcast techs out multiple times to trace the lines back to the poles.

>Replaced network cables between modem and the switch with a new, molded CAT6 cable.

  Link speed always shows 1Gb on all router ports.

>Invoked Plenish lore to drive evil spirits from the network setup and into the comcast technician.

 

 

 

If anyone can tell me where the "bad" is, I'd appreciate it. There is a hope that it's simply

something stupid I've done in the device configuration. I appreciate any help or advice.

 

All the best,

B

New Member
Posts: 6
Registered: ‎09-23-2014

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

[ Edited ]

Even if no one knows, I'd appreciate any advice on how I might generically go about further testing
and verification of the problem's source.

All the best.

Veteran Member
Posts: 6,104
Registered: ‎01-04-2017
Kudos: 886
Solutions: 314

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

Have you checked the CPU usage during this slowdown?
New Member
Posts: 6
Registered: ‎09-23-2014

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

Yep.  CPU is floating around 0-8% for the most part.

Veteran Member
Posts: 6,104
Registered: ‎01-04-2017
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Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

I mean, it sounds like a provider problem to me, maybe your on a congested line?
New Member
Posts: 6
Registered: ‎09-23-2014

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

[ Edited ]

To me as well.

 

This is a business connection, but Comcast has recently pushed back that they don't see anything

on their network.  In the past they claimed to have seen signal issues.  Last call, I was adament they

set up monitoring and a T2 rep called to confirm monitoring was setup.  The claim was they didn't see

any obvious issues from the modem's signal parameters, while on the phone, and the downsteam

slowdown was still happening.

 

I recently ran iperf3 on the edgelite to test bandwith and got simmilar results to what was

had via speed test on network-connected machines in browser.  The only connections involved

in that iperf3 test are:  modem -> a replaced, molded cat6e wire --> router.  So, it's the router,

comcast, or other darkforces are conspiring against plans which involve having a nice internet.

 

Downsteam randomly slows, so onward I go playing the game of "who-dun-it".

Veteran Member
Posts: 6,104
Registered: ‎01-04-2017
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Solutions: 314

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

try running MTR during the slowdown/ It should help you find where its happening
New Member
Posts: 6
Registered: ‎09-23-2014

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

[ Edited ]

Like a pathping?

 

I didn't see any odd latency on pathping when reaching to google and a few other test destinations.

 

 

Veteran Member
Posts: 6,104
Registered: ‎01-04-2017
Kudos: 886
Solutions: 314

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

Well the final thing would be to throw another random router in and see if it continues to happen
New Member
Posts: 22
Registered: ‎11-10-2014
Kudos: 3
Solutions: 1

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

Could an Ethernet port autonegotiation be droping down to 10Mbit? Have seen with a faulty cable.

Highlighted
New Member
Posts: 6
Registered: ‎09-23-2014

Re: Edgerouter Lite Random Slow Download Speeds, upload fine.

[ Edited ]

Chasing this at the momment:

 

https://community.ubnt.com/t5/EdgeMAX/Setting-port-to-100-Full-Duplex/td-p/1133395

 

 

According to the edgelite, it's auto negoatiated at 1Gb full duplex on eth0 connected to the modem.

I'm waiting for comcast to get back to me and see if anything is down negotating on their modem's

end.  Mind you, this has happened across 3 different brands of modem, so it must be something funny

the edgelite is doing.

 

All I can do is order something that isn't an edgelite, I suppose, for testing.

 

Refresh:  iperf3 is crap when the rest of the downsteam network is bad, so it MUST be between

the ethernet link from the router to modem.  This cable has been replaced 3 times with diffrent,

molded brands.