DSL-AC68U not resolving DNS

[Sash]

Hi, I have had a ASUS DSL-AC68U for about 2 years now on ADSL, and VDSL has become available in my area so i switches about a month ago.
While on ADSL i had adaptive QoS running nicely and also traffic Analyzer. Also DNS was set on the WAN side, and there was no DNS set on the LAN side, so simply using the DNS masq i have been reading about. The firmware upgrade/check for newer firmware also worked well.
When i switched from ADSL to VDSL, had some issues and reset to defaults with the factory reset and started fresh. I was running firmware version 3.0.0.4.380_7712, reset to default, stayed on the same firmware.

Since i reset to default, and got connected to VDSL, DNS has never worked. As in put the dns under the WAN settings, and the router can not resolve the time server or complete any nslookups. Also i have to set the DNS server on the LAN or my clients can not resolve names when the dns server is the router via DHCP.
It seems like DNS is not running.
I also can not get traffic Analyzer working either. This was working before too (i am thinking it maybe because dns isnt working, it cant get an NTP update, but just a thaught).

So i rolled back the firmware the other night to see if it made a difference, but it didnt. I did erase nvram after the roll back last night (mtd-erase2 nvram)
I am now running firmware 3.0.0.4.380_4026-g24cd33e
Ultimately i would like to get back to the newer firmware, but mostly i would like to to work properly with dns pointing o the router and the router caching the DNS results and traffic analyzer working again.

With out DNS working, it also cant check for newer firmware versions.
Here is what happens when i try to make the router complete an nslookup

Any ideas on how to help figure this out?
Been googling the sh!t out of this, but doesn't exactly look like a common issue.
Let me know if more config details are required.
Thanks

 

[bbunge]

Did you try a manual DNS setting? Google usually works for me 8.8.8.8 and 8.8.4.4

Sent from my P01M using Tapatalk

 

[Sash]

Yeah, all my setting are manaul. As in the advise a static ip, subnet, gateway and dns.
Have tried multiple DNS address and still nothing.
All the DNS servers i have tried work on my computer fine btw.

 

[Sash]

So i found out some more tonight.
I have the settings below in the snip

The traffic analyzer is based on a correct time, so setting the time manually this instantly started working.
So the main issue is dnsmasq
Looking through the config i came across a line
servers-file=/tmp/resolv.dnsmasq
opening that file, it is empty.
So i populated it with the dns servers, and killed the process dnsmasq. It starts up its self after about a minute or so.
Then all is fine. NTP went out and got its self sorted too.
I even removed the static DNS ip on the LAN side DHCP server and once again clients use dnsmasq for dns.
Which now works the way it is inteded to work.
The issue is why doesnt this file create when creating the WAN type as per the setting int he below snip.
After i reboot it it looses these settings so i dont want to have to keep putting these settings in.

Anyone have any ideas?

 

[ColinTaylor]

Looking through the config i came across a line
servers-file=/tmp/resolv.dnsmasq
opening that file, it is empty.

That's normal.

What you should see in the config file is:

resolv-file=/tmp/resolv.conf

and in /tmp/resolv.conf should be your external DNS servers, i.e.

# cat /tmp/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4

 

[Sash]

Hi Colin, thanks for the reply. The problem is that the resolve. Conflict file is empty.
I have to edit it myself for it to work.
When I reboot it the resolve.conf file is blank everytime.
If I edit it and add in that detail, it works, but i shouldn't have to edit that file everytime on reboot.

Any ideas why it's not creating the file and just have to add it in?

 

[ColinTaylor]

I can't think why it's not working. If it was a bug I would expect other people to be reporting it.

Can you post the contents of /etc/dnsmasq.conf please.

And

nvram show | grep ^wan | grep dns | sort

 

[Sash]

Will post thos details tonight. At work now. Thanks for your assistance.

 

[Sash]

Here is the output as its running

admin@(none):/tmp/home/root# cat /etc/dnsmasq.conf
pid-file=/var/run/dnsmasq.pid
user=nobody
bind-dynamic
interface=br0
interface=ppp1*
no-dhcp-interface=ppp1*
resolv-file=/tmp/resolv.conf
servers-file=/tmp/resolv.dnsmasq
no-poll
no-negcache
cache-size=1500
min-port=4096
domain=Home
expand-hosts
dhcp-range=lan,192.168.1.2,192.168.1.254,255.255.255.0,86400s
dhcp-option=lan,3,192.168.1.1
dhcp-option=lan,15,Home
dhcp-option=lan,44,0.0.0.0
dhcp-option=lan,252,"\n"
dhcp-authoritative
read-ethers
admin@(none):/tmp/home/root# cat /tmp/resolv.conf
admin@(none):/tmp/home/root# cat /tmp/resolv.dnsmasq
server=130.95.228.8
server=139.130.4.4
admin@(none):/tmp/home/root# nvram show | grep ^wan | grep dns | sort
size: 55593 bytes (9943 left)
wan0_dns1_x=139.130.4.4
wan0_dns2_x=130.95.228.8
wan0_dns=
wan0_dnsenable_x=1
wan0_xdns=
wan1_dns1_x=
wan1_dns2_x=
wan1_dns=
wan1_dnsenable_x=1
wan_dns1_x=139.130.4.4
wan_dns2_x=130.95.228.8
wan_dns=
wan_dnsenable_x=1
admin@(none):/tmp/home/root#

 

[Sash]

And after a reboot i did the same commands

admin@(none):/tmp/home/root# cat /etc/dnsmasq.conf
pid-file=/var/run/dnsmasq.pid
user=nobody
bind-dynamic
interface=br0
interface=ppp1*
no-dhcp-interface=ppp1*
resolv-file=/tmp/resolv.conf
servers-file=/tmp/resolv.dnsmasq
no-poll
no-negcache
cache-size=1500
min-port=4096
domain=Home
expand-hosts
dhcp-range=lan,192.168.1.2,192.168.1.254,255.255.255.0,86400s
dhcp-option=lan,3,192.168.1.1
dhcp-option=lan,15,Home
dhcp-option=lan,44,0.0.0.0
dhcp-option=lan,252,"\n"
dhcp-authoritative
read-ethers
admin@(none):/tmp/home/root# cat /tmp/resolv.conf
admin@(none):/tmp/home/root# cat /tmp/resolv.dnsmasq
admin@(none):/tmp/home/root#
admin@(none):/tmp/home/root# nvram show | grep ^wan | grep dns | sort
size: 55556 bytes (9980 left)
wan0_dns1_x=139.130.4.4
wan0_dns2_x=130.95.228.8
wan0_dns=
wan0_dnsenable_x=1
wan0_xdns=
wan1_dns1_x=
wan1_dns2_x=
wan1_dns=
wan1_dnsenable_x=1
wan_dns1_x=139.130.4.4
wan_dns2_x=130.95.228.8
wan_dns=
wan_dnsenable_x=1
admin@(none):/tmp/home/root#

 

[Sash]

You can see from the first post that on every reboot i manually edit the resolv.dnsmasq file and add in the DNS servers.

 

[ColinTaylor]

One of your NVRAM variables appears to be set differently from my RT-AC68U. Can you try this:

nvram set wan0_dnsenable_x=0
nvram set wan_dnsenable_x=0
nvram commit
reboot

Also your hostname appears to be invalid:

admin@(none):/tmp/home/root#

"(" and ")" are not valid characters for a hostname and might cause unpredictable behaviour. Did you set this hostname? Can you issue these commands please:

hostname
cd /etc
cat hosts
nvram show | grep none | sort


The only thing that looks wrong in your dnsmasq.conf file is this line:

dhcp-option=lan,44,0.0.0.0

which is meant to be the IP address of a WINS server. It might be normal for the DSL- or it might be a symptom of your DNS issue.

 

[Sash]

Here is the output regarding hostname, will take a look at the other settings now too. I dont recall setting a hostname, or seeing where i have the ability to set a hostname.

admin@(none):/tmp/home/root# hostname
-sh: hostname: not found
admin@(none):/tmp/home/root# cd /etc/
admin@(none):/tmp/etc# cat hosts
127.0.0.1 localhost.localdomain localhost
192.168.1.1 router.asus.com
192.168.1.1 www.asusnetwork.net
192.168.1.1 www.asusrouter.com
192.168.1.1 DSL-AC68U-2658.Home DSL-AC68U-2658
admin@(none):/tmp/etc# nvram show | grep none | sort
size: 55600 bytes (9936 left)
fw_log_x=none
switch_wantag=none
wans_dualwan=dsl none
wl0.1_auth_mode=none
wl0.2_auth_mode=none
wl0.3_auth_mode=none
wl0_auth_mode=none
wl1.1_auth_mode=none
wl1.2_auth_mode=none
wl1.3_auth_mode=none
wl1_auth_mode=none
wl_auth_mode=none

 

[ColinTaylor]

It looks like the hostname is correct. That's probably normal for the DSL- routers.

 

[Sash]

So i also set the setting mentioned above to no avail. Below is the output after a reboot.
You can see wan0 set its self back to option 1 (i assume that means false, where as 0 is true?)
And you can see that the resolv.dnsmasq was empty.
I also manually edited the resolv.dnsmasq after the reboot and checked the dnsenable setting was set to 0 and reboot again, but nothing, back to the resolve.dnsmasq file being empty.
Thanks for your assistance, any more ideas?


admin@(none):/tmp/home/root# cat /tmp/resolv.dnsmasq

admin@(none):/tmp/home/root# nvram show | grep ^wan | grep dns | sort
size: 55555 bytes (9981 left)
wan0_dns1_x=139.130.4.4
wan0_dns2_x=130.95.228.8
wan0_dns=
wan0_dnsenable_x=1
wan0_xdns=
wan1_dns1_x=
wan1_dns2_x=
wan1_dns=
wan1_dnsenable_x=0
wan_dns1_x=139.130.4.4
wan_dns2_x=130.95.228.8
wan_dns=
wan_dnsenable_x=1
admin@(none):/tmp/home/root#

 

[ColinTaylor]

And you can see that the resolv.dnsmasq was empty.

/tmp/resolv.dnsmasq is meant to be empty.
/tmp/resolv.conf is where I would expect to see your name servers.

If nvram set wan0_dnsenable_x=0 won't stick, try this instead:

nvram set wan0_dns="139.130.4.4 130.95.228.8"
nvram commit
reboot

 

[Sash]

Ohh, resolve.conf...
When i set the resolve.dnsmasq file to server=x.x.x.x is when it started working.

Either way its working now!!!!!
very happy.

So what i did was run the command
nvram show | grep dns | sort
to show all the config regarding DNS. Then set all the following settings manually
wanx_dnsenable_x=0
as well as setting the dns servers in the nvram file.
This seemed to fix it, although overkill most likely as i set much more than required.
I can also see it set these settings its self

wan0_xdns=139.130.4.4 130.95.228.8
wan0_dns=139.130.4.4 130.95.228.8

so must have been something to do with dns on the interface.
very wierd to me that it was working fine, then after reset to defaults i get all this hassle...
Oh well im happy its working now, and a HUGE THANK YOU to ColinTaylor for all your help. Couldn't have done it without you.

 

[Sash]

Once up and running, also tried changing the DNS settings from the gui. It worked. rebooted, still working.
Changed back to original DNS servers, rebooted and it is working fine.
Very happy at the bottom of this, has been bugging me for about 1 month now.
Have seen other dead end forums around regarding this so hopefully can help some others too.

 

[ColinTaylor]

Glad you got it working.

For reference, wan0_dnsenable_x tells the router whether to use static DNS values or get them automatically from the ISP.

wan0_dns1_x and wan0_dns2_x are the static values. wan0_dns is the dynamic values.

And wan0_... is the primary WAN interface and wan1_... is the secondary if you have one. wan_ are temporary variables.

With your previous ISP equipment were you using a WAN automatic IP? I suspect that switching to static may have messed up the NVRAM variables. Hopefully everything is in-sync again.

 

[Sash]

Yeah, it was all dynamic handed out by the ISP, so switching to static must have messed things up.
I am surprised that after multiple reset to defaults and deleting nvram (found other details of how to do it via command line) didn't resolve this issue.
Might go back and try and clean it up at some point with those last points, but leave it for now, its working. yay!