RT-N56U WAN link unstable?

[eltiel]

Can anyone please tell me what is going on here?

Oct 12 04:03:08 detect_link: WAN port link down detected!
Oct 12 04:03:10 detect_link: WAN port link restored!
Oct 12 05:09:26 detect_link: WAN port link down detected!
Oct 12 05:09:28 detect_link: WAN port link restored!
Oct 12 10:18:16 detect_link: WAN port link down detected!
Oct 12 10:18:18 detect_link: WAN port link restored!
Oct 12 10:23:14 detect_link: WAN port link down detected!
Oct 12 10:23:16 detect_link: WAN port link restored!
Oct 12 10:37:32 detect_link: WAN port link down detected!
Oct 12 10:37:34 detect_link: WAN port link restored!
Oct 12 10:37:38 detect_link: WAN port link down detected!
Oct 12 10:37:40 detect_link: WAN port link restored!
Oct 12 10:37:42 detect_link: WAN port link down detected!
Oct 12 10:37:46 detect_link: WAN port link restored!
Oct 12 10:37:50 detect_link: WAN port link down detected!
Oct 12 10:37:54 detect_link: WAN port link restored!
Oct 12 10:37:56 detect_link: WAN port link down detected!
Oct 12 10:37:58 detect_link: WAN port link restored!
Oct 12 10:38:02 detect_link: WAN port link down detected!
Oct 12 10:38:04 detect_link: WAN port link restored!
Oct 12 10:38:06 detect_link: WAN port link down detected!
Oct 12 10:38:08 detect_link: WAN port link restored!
​

The above happens randomly throughout the day, even when nobody use the Internet or is even at home. I only lose Internet connection during the few seconds when the WAN link goes up and down as it seem to always recover itself but the link state of my WAN connection often downgrades to 100mbps from 1000mbps. This somehow causes my WAN speed to be less than what I'm supposed to be getting although its nowhere near 100mbps (when link state is 1000mbps, I can get full 30mbps DL but when link state is 100mbps I can only get about 10-15mbps)

I assumed it was some cabling issues but I re-did my RJ45 keystone jacks multiple times. I have 2 lengths of Cat5e cables running through the same course but are fully independent, I tried using both of them but the results are the same.

Can anyone shed some light on what's happening here? It's really frustrating.

 

[eltiel]

OK so this is getting even more perplexing. A bit of background story:

Original setup:
Cable connecting router to modem is approximately 20 meters while PC is close by the router.

Modem =======[20m]======= Router === [2m] === PC


Test setup:
I used the very same RJ45 cables and somewhat rearranged the order.

Modem ===[2m]=== Router ========[20m]======= PC


The test setup works absolutely fine. I know this immediately points to the 20m cable being the culprit but the PC is running 1Gbps just fine with the cable. Zero packet loss during my ping flood test.

The only logical explanation I can think of is that the modem's wire transmission strength is not 'strong enough' to make it through the 20m cable in a stable manner, but the more capable PC NIC has no issues. This would also mean that there is some degradation going on as my setup hasn't changed in the past year. Does this explanation make sense and is it even plausible?

 

[john9527]

Or you had a bad plug connection, and just replugging the cables fixed it. Have you tried going back to the original configuration?

 

[eltiel]

Or you had a bad plug connection, and just replugging the cables fixed it. Have you tried going back to the original configuration?

Before changing the configuration, I've tried absolutely everything I can think of:
- Replugged them repeatedly
- Re-punched the keystone jacks
- Tested the cables using an electronic cable tester

 

[slyphnier]

if this just happen recently
i suggest, if possible, try plug directly to modem (skip the router)

on some modem/ONT(for FTTH), when the WAN connection down (or even just RTO) it take down the every other access, even like ping-in the modem
(basically the modem/ont like restarting, but its not completely restart it just try to resync the connection)
this happen most on cheap-low-end model

for this kind of issue, in the end its not router or modem issue
its all about your isp connection issue
when your isp connection stable you wont get this issue

 

[eltiel]

if this just happen recently
i suggest, if possible, try plug directly to modem (skip the router)

on some modem/ONT(for FTTH), when the WAN connection down (or even just RTO) it take down the every other access, even like ping-in the modem
(basically the modem/ont like restarting, but its not completely restart it just try to resync the connection)
this happen most on cheap-low-end model

for this kind of issue, in the end its not router or modem issue
its all about your isp connection issue
when your isp connection stable you wont get this issue

I'm not sure how that will help as I've quite clearly established that the problem lies somewhere within the cable configuration, and not the ISP.

 

[slyphnier]

I'm not sure how that will help as I've quite clearly established that the problem lies somewhere within the cable configuration, and not the ISP.

oh from what you saying on first post

I only lose Internet connection during the few seconds when the WAN link goes up and down as it seem to always recover itself but the link state of my WAN connection often downgrades to 100mbps from 1000mbps.

you saying u losing internet connection for few seconds, so i thought what i mention is possible case

anyway if the signal strength not strong/stable enough for 20m in like u mention on 2ndpost
not sure what you can do with it
you can try to upgrade your cable with better quality one, and try use Cat6 cable instead
but i am not sure if this will fix your issue