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DNS stops working?

stoneyard
Dabbler
Posts: 13
Registered: 01-09-2009

DNS stops working?

I have recently returned to plusnet after sometime with talk talk
Everything seems to be ok, apart from about 10 o'clock at night when my DNS stops working on my wireless devices,  A reboot of the router fixes this.
My pc connected via lan cable still works.
Any suggestions?
33 REPLIES
bradw
Grafter
Posts: 105
Registered: 21-05-2013

Re: DNS stops working?

If you're on windows, try this when it stops working:
windows key + r
type "cmd" without quotes and hit enter
type "nslookup example.com" without quotes and hit enter
copy/paste or screenshot the output, it may give some insight as to where the failures are occuring
Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: DNS stops working?

stoneyard
Dabbler
Posts: 13
Registered: 01-09-2009

Re: DNS stops working?

Hi All
As requested nslookup response posted here

Top line is when working, bottom when it stops.
This is working off a wired connection.
Cheers
Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: DNS stops working?

The symptoms you are describing sound somewhat similar to those on the thread I've linked above.
Are you finding this occurring regularly at other times as well?
Initially you seemed to think it was only affecting your wireless, but your last post suggests that the PC via LAN is affected, whereas previously it seemed to be still working - previously what was the PC doing at that time - not on a skype call by any chance?
Next time you get this occurring, don't reboot the modem/router, run a few more checks from the command prompt -Try each of  the following in succession -
nslookup ntp.plus.net
nslookup ntp.plus.net 192.168.1.254
nslookup ntp.plus.net 4.2.2.3
nslookup ntp.plus.net 212.159.6.9
nslookup ntp.plus.net ntp.plus.net
ping ntp.plus.net
ipconfig /flushdns
tracert ntp.plus.net
Also instead of rebooting, see if the problem ceases by itself with about 15 minutes and then repeat the last tracert command.
Edit: Sorry, forgot to ask, are you on ADSL or FTTC, has the (Modem)/Router got the USB port on it and which Firmware version is on it?
Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: DNS stops working?

Put a ping 8.8.8.8 on the front of that list in my last post as well.
pwatson
Rising Star
Posts: 2,468
Thanks: 8
Fixes: 1
Registered: 26-11-2012

Re: DNS stops working?

Also worth checking the basics of the wireless LAN connection - Has its DHCP lease been correctly renewed? 
Can you ping the router (192.168.1.254)
Can you ping something on the internet by IP address - As suggested above, ping 8.8.8.8
   
Post the results of 'ipconfig /all' from a command prompt when the WLAN isn't working.
Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: DNS stops working?

Quote from: stoneyard
As requested nslookup response posted here
This is working off a wired connection.

I assume you meant those results were from a wired connection and hence the 2nd paragraph of my reply #4.
Certainly worth checking if the Router responds to a ping, I can' t remember whether mine did or not  Embarrassed  so a revised list -
ping 192.168.1.254
ping 8.8.8.8
nslookup ntp.plus.net
nslookup ntp.plus.net 192.168.1.254
nslookup ntp.plus.net 4.2.2.3
nslookup ntp.plus.net 212.159.6.9
nslookup ntp.plus.net ntp.plus.net
ping ntp.plus.net
ipconfig /flushdns
tracert ntp.plus.net
Keep a note of the times you see the problem happening, I suspect you will find a regular pattern Huh
If you spot when the problem starts, don't forget to see if it goes away within 15 minutes.
If only WLAN or only LAN is displaying a problem then ipconfig /all is worth doing just to check all is well there.
stoneyard
Dabbler
Posts: 13
Registered: 01-09-2009

Re: DNS stops working?

Hi all
latest update
ping 192.168.1.254 - works
ping 8.8.8.8 -works
nslookup ntp.plus.net - fails DNS request times out
nslookup ntp.plus.net 192.168.1.254  - fails DNS request times out
nslookup ntp.plus.net 4.2.2.3 - works
nslookup ntp.plus.net 212.159.6.9 -works
nslookup ntp.plus.net ntp.plus.net - fails cannot find address
ping ntp.plus.net -fails
ipconfig /flushdns - flsuhed
tracert ntp.plus.net -cannot resolve address
checked ipconfig - lease still ok
did /release and /renew - no change
didn't fix after 15 minutes
jimbof
Grafter
Posts: 348
Thanks: 2
Registered: 02-05-2013

Re: DNS stops working?

Which router is this?  Sounds like the DNS proxy server has died in the router (I used to see this fairly often on older ADSL routers). 
pwatson
Rising Star
Posts: 2,468
Thanks: 8
Fixes: 1
Registered: 26-11-2012

Re: DNS stops working?

A real puzzle as to why it only fails on the wireless LAN though...
Community Veteran
Posts: 2,274
Thanks: 109
Fixes: 4
Registered: 18-02-2013

Re: DNS stops working?

Mine fails quite a bit, depends on what the kids are doing to make it fall over, when it does i just reset with the following commands.
or just specify DNS per item.
dns server route list
dns server route flush
dns server route add dns=212.159.6.9 metric=1 intf=Internet
dns server route add dns=212.159.6.10 metric=2 intf=Internet
dns server route list
saveall
jimbof
Grafter
Posts: 348
Thanks: 2
Registered: 02-05-2013

Re: DNS stops working?

if it fails fairly often wouldn't you be better off reconfiguring your DHCP server to dish out a couple of public DNS server address instead of the local faulty proxy?
I think the following would work perhaps...
dhcp server config state=disabled
dhcp server pool config name LAN_custom localdns=disabled
dhcp server pool config name LAN_custom primdns=>first DNS server ip<
dhcp server pool config name LAN_custom secdns=>second DNS server ip<
dhcp server config state=enabled
dns server config state=disabled
saveall
stoneyard
Dabbler
Posts: 13
Registered: 01-09-2009

Re: DNS stops working?

the router is only 3 weeks old
Should I be asking for a replacement?
Community Veteran
Posts: 2,274
Thanks: 109
Fixes: 4
Registered: 18-02-2013

Re: DNS stops working?

Buying a proper Router would solve your problem stoneyard, but you may think you've just been mugged though like most people around here.
the problems this router causes must be a nightmare for Plusnet!