RT-AC86U - Configure Ethernet

[ColinTaylor]

When something similar was discussed before it was my understanding that auto-negotiation is mandatory for 1000BASE-T.

https://www.snbforums.com/threads/force-lan-1-to-1000fd.27258/#post-207131

That was also my own experience when I used to work on Cisco enterprise kit.

 

[RMerlin]

Maybe the spec for 1000M required auto to be on

That's what I always heard. The interface needs to be able to downgrade in case the link isn't stable enough (due to length or wiring issues).

If a link randomly drops to 100 Mbps, then there's an issue with the interfaces or the wiring. Forcing it to 1 Gbps won't fix the issue, you will end up with lost packets and other random issues. I'd replace the network cable, and if it still fails then I'd insert an entry level switch between both devices (some people resolved compatibility issues that way with some crappy cablemodems in the past).

 

[ApexRon]

That's what I always heard. The interface needs to be able to downgrade in case the link isn't stable enough (due to length or wiring issues).

If a link randomly drops to 100 Mbps, then there's an issue with the interfaces or the wiring. Forcing it to 1 Gbps won't fix the issue, you will end up with lost packets and other random issues. I'd replace the network cable, and if it still fails then I'd insert an entry level switch between both devices (some people resolved compatibility issues that way with some crappy cablemodems in the past).

There is no cable issue as long as the device is taken out of sleep mode. The router knows that a cable is plugged in and right now it looks like the port initiates an auto-negotiate every 30 to 60 seconds, marking the port as up, and then it marks the port down 20 to 30 seconds after that. However, since I made the change, the speed never changes. Other ports, with no cables, don't post to system log.

 

[RMerlin]

There is no cable issue as long as the device is taken out of sleep mode. The router knows that a cable is plugged in and right now it looks like the port initiates an auto-negotiate every 30 to 60 seconds, marking the port as up, and then it marks the port down 20 to 30 seconds after that. However, since I made the change, the speed never changes. Other ports, with no cables, don't post to system log.

You can check the stability of your network connection using netstat -s (assuming the client device runs Windows). Look for errors.

 

[ApexRon]

You can check the stability of your network connection using netstat -s (assuming the client device runs Windows). Look for errors.

From the router:
eth4 Link encap:Ethernet HWaddr 4C:...
inet6 addr: fe80::... Scope:Link
UP BROADCAST RUNNING ALLMULTI MULTICAST MTU:1500 Metric:1
RX packets:10718836 errors:0 dropped:0 overruns:0 frame:0
TX packets:54400311 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:927012926 (884.0 MiB) TX bytes:817027642 (779.1 MiB)

The connected device is an AppleTV 4k so no real stats available though I have a speed test app that will post errors of which there never has been any. The speed test shows a download of 235mbps and an upload of 11.5mbps.

 

[GrinningShark]

Would be nice if there was a switch in the GUI to easily disable logging for the 4 ethernet ports (versus ssh tweaks). When my iMac is sleeping, it generates a lot of log spam as the port drops to low power and back again. I don’t recall the 68U or 5800 creating all the log spam.

 

[ApexRon]

Would be nice if there was a switch in the GUI to easily disable logging for the 4 ethernet ports (versus ssh tweaks). When my iMac is sleeping, it generates a lot of log spam as the port drops to low power and back again. I don’t recall the 68U or 5800 creating all the log spam.

I agree. I have a wifi device (LaCrosse weather station) that, as per manufacturer, turns off the wifi adapter to conserve battery power, even though it is using an AC adapter. The RT-AC86U logs; "Aug 27 11:29:23 roamast: eth6: add client [d8:...] to monitor list".

 

[RMerlin]

The Ethernet driver is closed source and outside of my control.

 

[Darcy]

Setup the 86U yesterday and my upload speeds were cut in half. Setting issue?


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[ApexRon]

Setup the 86U yesterday and my upload speeds were cut in half. Setting issue?


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Assuming that this is a new installation, make sure that you have the latest firmware. If your upload speed is still ½ advise as to media being used, what if anything changed from prior installation (cable, network design, ...), and anything else that could be relevant.

 

[OzarkEdge]

Setup the 86U yesterday and my upload speeds were cut in half. Setting issue?


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You should start a new thread to discuss your issue.

OE

 

[mlord]

Good information in this thread, so thanks to all who have contributed!

I had a minor issue here where, perhaps once every week or two, the ethernet connection between my cable modem and the RT-AX86U would drop to 100FD and stay there, severely limiting the much faster ISP connection.

The cabling all looks fine and normally works fine at 1000FD. There are however several plugs and jacks en-route to the patch panel and back, so I suspect temperature swings in the house may be causing some slight movement in the connectors and triggering this behaviour once in a while (it is WINTER here, so the inside of the home swings from 18C overnight to 27C during daytime when it is sunny outside).

Using info from this thread, I have added a background script on /jffs to periodically look for eth0 being up at 100FD, and then force it back to 1000FD when that happens. Works like a charm!

 

[kenshiroro]

Good information in this thread, so thanks to all who have contributed!

I had a minor issue here where, perhaps once every week or two, the ethernet connection between my cable modem and the RT-AX86U would drop to 100FD and stay there, severely limiting the much faster ISP connection.

The cabling all looks fine and normally works fine at 1000FD. There are however several plugs and jacks en-route to the patch panel and back, so I suspect temperature swings in the house may be causing some slight movement in the connectors and triggering this behaviour once in a while (it is WINTER here, so the inside of the home swings from 18C overnight to 27C during daytime when it is sunny outside).

Using info from this thread, I have added a background script on /jffs to periodically look for eth0 being up at 100FD, and then force it back to 1000FD when that happens. Works like a charm!

If its not too much trouble, can you please walk me through what you did? My WAN and LAN ports are all stuck at 100Mbps

AC86U on latest Merlin 386.4

 

[mlord]

This below is the script that is run periodically on the router. It checks for a downgraded 100FD on eth0 (my WAN port) and tells it to renegotiate for 1000FD whenever that's the case. In my setup, this is run from ANOTHER script I already have in the background that sits in a loop doing "sleep 15" and then running stuff including this:

#!/bin/sh
## Keep the Modem connection at full GigE speed.
## For some reason it periodically drops to 100mbit instead.
if ethctl eth0 media-type | grep -q "Link is Up at Speed: 100M" ; then
    sleep 2  ## wait, then check again to make sure it is stable
    if ethctl eth0 media-type | grep -q "Link is Up at Speed: 100M" ; then
        ethctl eth0 media-type 1000FD >/dev/null 2>&1
    fi
fi
exit 0

 

[kenshiroro]

This below is the script that is run periodically on the router. It checks for a downgraded 100FD on eth0 (my WAN port) and tells it to renegotiate for 1000FD whenever that's the case. In my setup, this is run from ANOTHER script I already have in the background that sits in a loop doing "sleep 15" and then running stuff including this:

#!/bin/sh
## Keep the Modem connection at full GigE speed.
## For some reason it periodically drops to 100mbit instead.
if ethctl eth0 media-type | grep -q "Link is Up at Speed: 100M" ; then
    sleep 2  ## wait, then check again to make sure it is stable
    if ethctl eth0 media-type | grep -q "Link is Up at Speed: 100M" ; then
        ethctl eth0 media-type 1000FD >/dev/null 2>&1
    fi
fi
exit 0

Thanks for your response

I need to find out how to install scripts onto the router

Is there a tutorial available?

 

[Jeffrey Young]

You will have to use Merlin's firmware and see the wiki below; look at user scripts

Home

Third party firmware for Asus routers (newer codebase) - RMerl/asuswrt-merlin.ng

github.com

 

[kenshiroro]

You will have to use Merlin's firmware and see the wiki below; look at user scripts

Home

Third party firmware for Asus routers (newer codebase) - RMerl/asuswrt-merlin.ng

github.com

I am currently on 386.4

I have checked the wiki prior to asking for help. I am not confident as to what i need to do or how as i am not experienced enough at this, hence me here asking for help

Worst case scenario is wrecking the modem without realizing

On that note, how would i go about reflashing back to the OFW?

 

[Jeffrey Young]

I suppose the first question would be "where are you know with the process?". I.e., have you SSH'd into the router? JFFS and User Scripts enabled (via the GUI Administration -> System)?

Second question would be what part are not cozy with? Happy to help as time permits, just don't want to ramble on with stuff you may already be past.

Basicly, we need to build a script for the content above, saving in JFFS or USB Drive, make it executable, then add a cron job add entry to the /jffs/scripts/services-start script. You can look in the Merlin Wiki on using cron.

As for switching back to the OEM software. Same process as you did with Merlin - Download the image from Asus's website, and use the firmware updater in Merlin or use the rescue mode.

 

[kenshiroro]

I suppose the first question would be "where are you know with the process?". I.e., have you SSH'd into the router? JFFS and User Scripts enabled (via the GUI Administration -> System)?

Second question would be what part are not cozy with? Happy to help as time permits, just don't want to ramble on with stuff you may already be past.

Basicly, we need to build a script for the content above, saving in JFFS or USB Drive, make it executable, then add a cron job add entry to the /jffs/scripts/services-start script. You can look in the Merlin Wiki on using cron.

As for switching back to the OEM software. Same process as you did with Merlin - Download the image from Asus's website, and use the firmware updater in Merlin or use the rescue mode.

Thank you so much for willing to help

The part where i am not cozy with would be the whole script building and execution part with cron entry. I'll go through the wiki again and hopefully all that makes sense to me

 

[Jeffrey Young]

OK, well, the hard work is already done. @mlord already made the script. You just need to copy the contents.

So, ssh into your router and change directory to somewhere on your jffs partition. Let's assume you are gonna put the script in the /jffs/scripts directory.

mkdir -p /jffs/scripts
cd /jffs/scripts

Use nano to make a new script

nano checkport.sh

Copy the script from above into the new file open. When you are done, ctrl-x will exit nano. It should ask you if you want to save, say yes.

Make the new script executable

chmod +x checkport.sh

Now you can test the script manually. When you notice a port has degraded, ssh into your router and manually run the script;

/jffs/scripts/checkport.sh and see if you get any errors.

Next step will be to make a cron job. Search the internet for "cron generator" and use any one that suits your fancy to make a cron job for examples on who cron job commands are structured.

Using nano, in the /jffs/scripts directory, edit the file "services-start" with nano, just as above. If services-start does not exits, create it, then in the file put;

#!/bin/sh

cru a CheckPort */15 * * * * /jffs/scripts/checkport.sh >/dev/null 2>&1

Exit nano and make the file executable

This will run the script every 15 minutes in my example. once the router is rebooted.

You can also add the cron job right away by just entering the cru a command at the command line.