RT-AC68P Gigabit Connection Issue - WAN and LAN Ports

[lokester]

LIKE LIKE LIKE the custom firmware RMerlin has provided us for the ASUS routers. Very good work. On my main router, RT-AC68P, after upgrading to 380.65, a few days later I found that I could no longer had a WAN connection with my Motorola SB6141 cable modem. Router message stated something like "ISP's DHCP not working correctly". After searching forums, I find this is not a new issue. I eventually followed advice from RMerlin and installed a 5 port gigabit switch between modem and router and re-established link to internet.

Problem then was that while the cable modem was linking with the new switch at gigabit speed, the link from switch to AC68P WAN port was only showing 10mb. Likewise, on the 4 LAN ports on the AC68P, only 3 of the 4 were showing "1000 Full Duplex" connection status on the TOOLS tab. Prior to the FW upgrade, all 4 LAN connections were 1000 Full Duplex. I swapped cables to CAT6, got shorter cables, etc. but never could get all devices to connect at GB status.

This morning, I reverted back to 380.62_1 FW and I can now again get an internet connection via WAN port connected directly to the cable modem (no intermediate switch required). The WAN connection is showing 1000 Full Duplex as well as LAN 1 and LAN 2 being 1000 Full Duplex, but the 2 PC's connected to LAN 3 and LAN 4 only showing connected at 10mb speed. For now, I moved them to a 8 port GB switch being fed from LAN1 port on the Router. Both PC's now linked up at 1000, so all is well.

Seems like the Firmware is having more to do with these GB link issues than any hardware. I normally like staying on the "bleeding edge" with the latest FW updates, but for now, will stay at version 62.

Anyone else having issues like me?

 

[catch36]

LIKE LIKE LIKE the custom firmware RMerlin has provided us for the ASUS routers. Very good work. On my main router, RT-AC68P, after upgrading to 380.65, a few days later I found that I could no longer had a WAN connection with my Motorola SB6141 cable modem. Router message stated something like "ISP's DHCP not working correctly". After searching forums, I find this is not a new issue. I eventually followed advice from RMerlin and installed a 5 port gigabit switch between modem and router and re-established link to internet.

Problem then was that while the cable modem was linking with the new switch at gigabit speed, the link from switch to AC68P WAN port was only showing 10mb. Likewise, on the 4 LAN ports on the AC68P, only 3 of the 4 were showing "1000 Full Duplex" connection status on the TOOLS tab. Prior to the FW upgrade, all 4 LAN connections were 1000 Full Duplex. I swapped cables to CAT6, got shorter cables, etc. but never could get all devices to connect at GB status.

This morning, I reverted back to 380.62_1 FW and I can now again get an internet connection via WAN port connected directly to the cable modem (no intermediate switch required). The WAN connection is showing 1000 Full Duplex as well as LAN 1 and LAN 2 being 1000 Full Duplex, but the 2 PC's connected to LAN 3 and LAN 4 only showing connected at 10mb speed. For now, I moved them to a 8 port GB switch being fed from LAN1 port on the Router. Both PC's now linked up at 1000, so all is well.

Seems like the Firmware is having more to do with these GB link issues than any hardware. I normally like staying on the "bleeding edge" with the latest FW updates, but for now, will stay at version 62.

Anyone else having issues like me?

Similar problem with an AC88U with 380.65 and a comcast gateway modem in bridge mode. Wan port of the AC88U unable to obtain a dhcp ip adress and I would get the erron on the router that there was a problem with the ISP DHCP. Older version of Merlin's 380 firware that had previsously worked no longer worked. I had to clone a mac adress from a pc to the router in order to obtain an ip address. Stangely Asus' firware for the router had no problem the gateway modem obtaining an ip address when installed on the router.

 

[lokester]

Trying to keep this post current as this seems to be a very common issue. Would be good to get it resolved, but need someone that knows more than I do. Appears to be firmware related.

 

[lokester]

After running 380.62_1 for a few days, I upgraded to 380.64_2. It ran for a day or two, but then it too eventually gave me the ISP DHCP service not working error message. I reloaded 380.62_1 and am back working, but there definitely seems to be issues with the RT-AC68 and both 380.64 and 380.65 firmware.

So I am seeing 2 different types of issues. 1st is the WAN port not getting an IP address assigned by the ISP. 2nd, I am seeing where the GB WAN and LAN ports are not connecting at GB speeds. Rolling back to 380.62_1 resolves both issues for this router.

Hoping RMerlin will offer input as to what is causing this issues.

 

[eddiez]

After running 380.62_1 for a few days, I upgraded to 380.64_2. It ran for a day or two, but then it too eventually gave me the ISP DHCP service not working error message. I reloaded 380.62_1 and am back working, but there definitely seems to be issues with the RT-AC68 and both 380.64 and 380.65 firmware.

So I am seeing 2 different types of issues. 1st is the WAN port not getting an IP address assigned by the ISP. 2nd, I am seeing where the GB WAN and LAN ports are not connecting at GB speeds. Rolling back to 380.62_1 resolves both issues for this router.

Hoping RMerlin will offer input as to what is causing this issues.

Don't think this is a FW issue. It's not a generic issue and could be either a hardware issue or cable issue.

 

[MarkRH]

I have a RT-AC68U connected to a Cisco DPQ3212 cable modem from Cox Communication. It's a 1 Gig connection to it and 1 Gig to my PC on port 1. There was an older FW version (380.60 and .61) where I was getting this ISP DHCP issue with disconnects and back then on the WAN tab I changed DHCP query frequency to Normal Mode from Aggressive Mode just to see what happened and have left it there since. Anyway, I've never seen the message and my speeds/connection have been fine with 380.65 and previous .64 versions. I've never seen 10mb. My TV and Blu-ray player always connect at 100mb as that is their port speed.

Anyway, if you haven't, try power cycling everything. Turn cable modem on first and let it do its thing. Then, turn on the router and finally the PC.

 

[lokester]

Eddie and Mark, thanks to both for your advice and for keeping this post current. No doubt I have reset power, unplugged cable modem for 30 minutes and reset the world. I have swapped cables, moved devices from one LAN port to another. The only thing I can find consistent is FW version and this particular ASUS router.

I can live with the older FW for now. When the next FW version is released, is there a way to format or "wipe clean" all prior versions and remnants of existing FW from the router before loading the new version?

Getting by for now. No real problem.

 

[lokester]

Eddie and Mark, thanks to both for your advice and for keeping this post current. No doubt I have reset power, unplugged cable modem for 30 minutes and reset the world. I have swapped cables, moved devices from one LAN port to another. The only thing I can find consistent is FW version and this particular ASUS router.

I can live with the older FW for now. When the next FW version is released, is there a way to format or "wipe clean" all prior versions and remnants of existing FW from the router before loading the new version?

Getting by for now. No real problem.

It seems my problem took care of itself. Woke up the other morning and my internet was down. My ASUS RT-AC68 bit the dust. Had a bad lightening storm during the night, so not sure if that is what took it out, or if it was on it's last leg and just time to quit. A few LEDs light up, but power LED is barely lit, I cannot get it to reset, go into rescue mode, reboot, nothing. I checked power supply and it is good.

Back running on my $9 Rosewill router running DDWRT. Not sure if I need to spend another $150 on a higher performance router or not.

Good forum. Always like reading up on stuff here.

 

[L&LD]

In the future, you can try following the links in the post below when your router exhibits random issues that don't seem to make sense.

https://www.snbforums.com/threads/ssid-broadcast-on-5g-band.37961/#post-312643

As far as spending $150 on a high performance router; yes!

Just make sure you have it behind a quality UPS if electrical storms and/or power outages are normal or frequent where you live (both can kill electronics easily or at least more quickly than a stable power source would allow).