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RT-AC86U - multiple link down errors

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blackhawktek

New Around Here
Guys,
Just installed Merlin (RT-AC86U_384.5_0.zip) on a new AC2900. I checked the logs this morning and theres several entries for Link UP and Link DOWN back to back to back. There are tons of these errors. The link UP always comes back up 2-3 seconds after it goes down.

Code:
Jul 6 05:00:00 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul 6 05:00:03 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex

Is this a device thats plugged in having issues? AC2900 issues?

Thanks for any input.
 
Any advice? Thanks!

Code:
Jul  8 13:23:44 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  8 13:24:31 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  8 13:24:32 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  8 13:24:34 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  8 13:24:36 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  8 13:24:40 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  8 13:24:42 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  8 13:24:44 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
 
Thanks. I changed cables to this device (raspberry pi) and it still did it. I moved the pi to a different port and it does NOT do it. I moved a different device/cable to eth4 and its doing the same DOWN/UP deal.

Is something screwy with the port ya think? The device seems to be functioning ok. I just bought it last week so it should be under warranty. I have already emailed their support but their email said it could take up to 48hrs for a reply.
 
Is something screwy with the port ya think? The device seems to be functioning ok. I just bought it last week so it should be under warranty.

From your description, yes. Just return/exchange for another unit from wherever you got this one, go the Asus/RMA route if that fails.
 
Same message was reported here (different port). Bear in mind that I think the logical/physical port numbering is reversed.

Might be an auto-negotiation problem, or maybe something to do with power saving modes.
 
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I see the same things in my logs occasionally on a 86. I don't think it causes any problems.

Jul 2 22:14:36 kernel: eth1 (Ext switch port: 0) (Logical Port: 8) Link DOWN.
Jul 2 22:14:47 kernel: eth1 (Ext switch port: 0) (Logical Port: 8) Link UP 100 mbps full duplex
Jul 2 22:17:22 kernel: eth1 (Ext switch port: 0) (Logical Port: 8) Link DOWN.
Jul 2 22:17:32 kernel: eth1 (Ext switch port: 0) (Logical Port: 8) Link UP 100 mbps full duplex
Jul 3 00:36:43 kernel: eth3 (Ext switch port: 2) (Logical Port: 10) Link DOWN.
Jul 3 00:36:45 kernel: eth3 (Ext switch port: 2) (Logical Port: 10) Link UP 1000 mbps full duplex
 
I have the same issue. On mine it is always a computer going on/off that creates the message. Never happened with previous Asus routers but seems unique to the 86U. Others have reported the same issue. Doesn't seem to cause any problems, and yes, the port numbers are reversed.
 
Thanks guys. I have a case opened with Asus. I will report back with what they say.
Since I plugged in both a Raspberry Pi and an Xbox with different network cables, and they're both doing it, I'm suspicious. I just want to stay vigilant while its under warranty :)

This is happening all day, every day:
Code:
Jul  9 20:55:53 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:55:56 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 20:56:06 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:56:09 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 20:58:36 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:58:39 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 20:59:17 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:59:21 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 20:59:53 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:59:56 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 21:00:07 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:00:10 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 21:03:48 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:03:50 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 21:03:56 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:03:59 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 21:07:48 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:07:50 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 21:07:57 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:08:00 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
 
Thanks guys. I have a case opened with Asus. I will report back with what they say.
Since I plugged in both a Raspberry Pi and an Xbox with different network cables, and they're both doing it, I'm suspicious. I just want to stay vigilant while its under warranty :)

This is happening all day, every day:
Code:
Jul  9 20:55:53 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:55:56 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 20:56:06 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:56:09 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 20:58:36 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:58:39 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 20:59:17 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:59:21 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 20:59:53 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 20:59:56 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 21:00:07 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:00:10 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 21:03:48 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:03:50 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 21:03:56 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:03:59 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex
Jul  9 21:07:48 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:07:50 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jul  9 21:07:57 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jul  9 21:08:00 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 10 mbps full duplex

Hi blackhawktek, I'm have the same log messages with my Asus RT-AC86U router. Did you ever get this resolved with Asus? Thanks!
 
Hi blackhawktek, I'm have the same log messages with my Asus RT-AC86U router. Did you ever get this resolved with Asus? Thanks!
Unfortunately, no. I couldn’t figure it out. I sent it back to newegg for a refund. I didn’t want to chance there was a hardware failure. Asus support via email wasn’t much help either. Sorry I’m not much help.
 
I had similar log entries. As I expected, it was caused by a bad cable connector. Cable replacement solved the problem.
 
Jan 24 10:00:51 peaches kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link DOWN.
Jan 24 10:00:51 peaches kernel: br0: port 4(eth4) entered disabled state
Jan 24 10:00:54 peaches kernel: eth4 (Ext switch port: 3) (Logical Port: 11) Link UP 1000 mbps full duplex
Jan 24 10:00:54 peaches kernel: br0: port 4(eth4) entered forwarding state
Jan 24 10:00:54 peaches kernel: br0: port 4(eth4) entered forwarding state

Fixed the log errors by removing the RJ45 cable that was plugged between router and unused second port on PC.
Maybe that helps someone else before sending it back in.
 
I had the same issue on my ax86u, 386.3_2, network were completely down, but wifi still working.
Changing to a different port didn't work, changing different cable didn't work, restarting computer worked for a while and gone bad again, maybe my computer LAN port was broken.

Code:
Dec  7 20:22:29 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:22:31 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:23:02 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:23:04 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:23:28 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:23:31 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:23:55 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:23:57 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:24:21 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:24:24 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:24:48 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:24:50 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:25:15 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:25:18 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:25:42 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:25:45 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:26:09 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:26:11 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:26:35 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:26:37 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:27:02 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:27:04 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
Dec  7 20:27:28 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link DOWN.
Dec  7 20:27:31 kernel: eth4 (Ext switch port: 3) (Logical Port: 11) (phyId: b) Link Up at 1000 mbps full duplex
 
Last edited:

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