RT-AC68U with 380.63_2 DNS problems

[ghus]

I have 3 identical routers RT-AC68U that are setup as router -> repeater -> bridge configuration. When I installed in all 3 of them the latest 380.63_2 I run into several problems.

1) The most important is the DNS issue that started to affect and deteriorated within 24 hours. First off let me clarify that I use opendns in my settings. During the first day I could experience some minor delays in browsing. By the next day those delays became timeouts. While I was experiencing those timeouts I did some internal tests to make sure other servers in my network were accessible and the problem was indeed related to external sites and name resolution. All internal tests were successful and I was able to stream files internally. Problem was not isolated to repeater or media bridge, even hosts connected to router experienced the outage. After reboot the problem gets fixed but deteriorates within 24 hours.

2) Reduced throughput. I also realized that the throughput was significantly reduced. In my test I am using a host connected on the media bridge and a host connected on the router, using the repeater in the middle. With the latest firmware the maximum throughput I was able to achieve was around 90 to 100 mbps. This was less compared to the performance using an oldest firmware 378.56_2 with which I scored north of 130mbps.

I ended up going back to 378.56_2. With this firmware everything is way more stable. DNS is working right and speeds are great. I'd rather use the newest firmwares since they include security updates and updated services like openvpn etc, but if things are more stable with 378 what can I do.

Is anybody else experiencing this with this router? I start to get the impression that with the new firmware 380.xx older routers get deprioritized. Not sure they behave their optimal with the latest firmware versions. Dont have an opinion regarding newer routers when it comes to stability since I dont own one.

On another note, are there any forks by any chance of the older firmware 378 that includes probably security updates and updated services like openvpn.

Regards

 

[martinr]

Could you give details of the DNS settings you have on the WAN page, the LAN page and any DNS filtering you have in place please?
Thanks.

 

[ghus]

On the router I have the following:
WAN: OpenDNS IPs
LAN: (DHCP) Empty. (this provides the router IP to internal hosts)

On the repeater:
LAN: Router IP

On the Media bridge:
LAN: Router IP

I used the same config in both firmware, latest 380 and the previous 378

 

[ghus]

Also I haven't tried any 380 revision other than the latest in router mode (380.63_2). Not sure if my problem is related to something recently introduced in 380 or all along. I just compared latest 380 with latest 378. And while I was on 380 I tried a few times factory reset from the UI and nvram reset from the wps button, just to make sure no leftover values would affect the firmware. Only reboot would resolve this problem. but then again it would come back by next day. weird !!

 

[martinr]

Your DNS settings seem good ro me. But I forgot to ask you: can you remember when you last carried out a restoration to factory default settings (RFDS) after a new firmware flash? I don't mean how many months ago but more in relation to the firmwares you were on prior to installing 380.63_2, and especially, which version were you on directly before flashing to that, and, did you RFDS after flashing 380.63_2?

Do you have anything plugged into the USB ports on your router, or any fancy, non-Merlin stuff running on the router?

 

[ghus]

For a few months now I was using version 380.58. The device itself was configured for years as an access point only while routing was done by a RT-16. No problems with this setup for years and years.

I decided to decommission the RT-N16 and convert the RT-AC68 to router mode at which point I upgraded from 380.58 to 380.63_2. I purchased a couple more of those and set em up as repeater and media bridge to extend network. After I converted my original from pure AP to router+AP I started to experience these DNS outages. I stayed like that for a good 4 to 5 days monitoring and debugging the ongoing problem. During that period and in my debugging attempts I did a bunch of resets in case that was the issue, while I had 380.63_2 on it. I did factory reset from the interface and also nvram with the WPS button sequence. After none of these attempts worked I decided to roll back to 378.56_2 since I now own 3 of those models connected wirelessly and figured that would give me the best millage regarding stability.

Its been 3rd day now and both name resolution seems to be snappy, browsing experience indicates that, and also wifi connectivity between the 3 units is great so far. I would rather use the new builds though cause and be current with security updates etc.

 

[martinr]

"I would rather use the new builds though cause and be current with security updates etc."

Quite right, too. Do any of the logs give anything away? I notice from my Connections log that my DNS connection shows as Assured. When your router goes awry, I wonder if your Connections log or Syslog give any clues?

And USB devices - anything plugged in? After you reset to factory default settings (RFDS), I don't suppose you ran it for a couple of days in a minimal state and then gradually introduced your personal settings?

My temptation would be, if you really get nowhere, to RFDS again but following L&LD's guidelines in his minimal and manual config eg in:
http://www.snbforums.com/threads/ho...he-original-asus-firmeware.34560/#post-279323

especially running the router in its minimal state for a while to test it, and only then gradually introducing your settings until you find the ones that seem to cause the problem, except life is never quite so simple! (I'm assuming that when you say you previously did an RFDS you restored all your settings immediately afterwards. It would be instructive to know if you have this problem in the minimal state.)

 

[ghus]

Logs are one thing i didn't check since i wasnt expecting any errors. Regarding settings i was inputing them manualy to be on the safe side i didn't flash any backed up config.

I only have a few port mappings, outbound blacklisted firewall rules and vpn users. Also no connected usb devices on this router. After each reset i would input my settings, didn't occur really to let it run on default state, cause i have been using those settings for many years on the rt-16.

Will have to do another run with default values

 

[martinr]

.

......,Will have to do another run with default values

Please let us know what happens; it's valuable feedback for the future. Good luck. (Sounds like a nice job to drag out over Christmas to get you away from the lobotomy screen in the lounge.)

 

[ghus]

lol ..true

 

[cniggeler]

Hi, realize this thread is old, but google searches have only revealed this type of error with this thread, so appreciate your patience and more importantly, your thoughts and assistance ;-)

The OP here mentioned this similar issue, although with OpenDNS, but seemed related not to the hardware but instead to the firmware version.

I keep getting DNS timeouts. I have configured three DNS servers (Verisign, OpenNIC, and Alternate DNS) in the RT-N16, and have also tried various other servers, all to no avail. As a workaround, I have set Google's public server as a secondary server in each computer's Network config.

My firmware version is DD-WRT v24-sp2 (06/08/12) mega - build 19342, which is old, but I only wanted a dd-wrt for wireless channel setting and at one time, iptables firewall.

Has anyone else experienced this, or have a version where the issue has gone away? Thanks!