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DNS weirdness

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Grafter
Posts: 21,036
Thanks: 2
Registered: ‎04-04-2007

Re: DNS weirdness

Hi there,
I'm sorry for both the problems you saw last night and foir the lack of a service status posting which was an oversight on our behalf.
Our networks team believe they fixed something this morning and we're hopeful that these issues are resolved.  Please do let us know if this is not the case.
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Community Gaffer
Community Gaffer
Posts: 14,570
Thanks: 2,182
Fixes: 152
Registered: ‎04-04-2007

Re: DNS weirdness

Quote from: Liam
Yep, I'm getting lagging DNS and timeouts again too this morning intermittently.

Quote from: RealAleMadrid
I still don't see any service status report for this problem.
Not impressed.

Everything at this side now appears to be working OK so I'm not sure a service status is necessary - unless of course you're still having problems?
Liam, shortly after you made that post we identified that a listener on one of the load balancers wasn't accepting requests for a particular caching DNS server. We restarted the DNS service which seemed to clear this problem.
After a bit more digging we've noticed that one of the gateways was having difficulty talking the master load balancer (for caching DNS requests). Since the 1st July it looks like it's been using the secondary load balancer instead. Interestingly enough this the gateway flipped back to using the master last night which happened around the same time DNS problems were being reported.
We've not got an awful lot to go on at the moment so we're currently making sure we've got better monitoring in place should we see a similar thing happen again.
If you are still having problems then you can help by providing some of the information I asked for a while back in the post here. I've summarised this below:
[quote author="Bob, the last time there were DNS issues"]Firstly, find out what of the 4 DNS addresses you are using. You might already know this however if you don't you should find the information on one of your router's status pages. Failing that, you can run the ipconfig command from a Windows command prompt:
Quote from: ipconfig
C:\Users\admin>ipconfig /all
Wireless LAN adapter Wireless Network Connection:
Connection-specific DNS Suffix . : lan
Description . . . . . . . . . . . : Intel(R) PRO/Wireless 3945ABG Network Con
nection
Physical Address. . . . . . . . . : 00-1B-77-C5-37-5E
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::6d63:2b26:cfac:4ead%10(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.65(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 23 April 2009 12:44:41
Lease Expires . . . . . . . . . . : 24 April 2009 12:44:41
Default Gateway . . . . . . . . . : 192.168.1.254
DHCP Server . . . . . . . . . . . : 192.168.1.254
DNS Servers . . . . . . . . . . . : 212.159.13.49 <--- If this shows your router's IP address then you'll need to look on your router status pages for the addresses you're using.
212.159.13.50
NetBIOS over Tcpip. . . . . . . . : Enabled

Secondly, run a traceroute from a Windows command line to each of the DNS addresses. This will tell us both what gateway you're connected to and which of the two loadbalanced sites your DNS traffic is going to.
Quote
C:\Users\admin>tracert 212.159.13.49
Tracing route to pth-cdns01.plus.net [212.159.13.49]
over a maximum of 30 hops:
1 89 ms 98 ms 99 ms dsldevice.lan [192.168.1.254]
2 58 ms 49 ms 70 ms lo0-plusnet.pte-ag2.plus.net [195.166.128.72]
3 38 ms 57 ms 36 ms ge0-0-0-504.pte-gw1.plus.net [84.92.4.89]
4 62 ms 52 ms 49 ms te2-2.pcl-gw01.plus.net [212.159.0.185]
5 84 ms 53 ms 47 ms vl63.pcl-lb01.plus.net [212.159.2.252]
6 40 ms 28 ms 31 ms pth-cdns01.plus.net [212.159.13.49]
Trace complete.

Quote
C:\Users\admin>tracert 212.159.13.50
Tracing route to pth-cdns02.plus.net [212.159.13.50]
over a maximum of 30 hops:
1 75 ms 99 ms 98 ms dsldevice.lan [192.168.1.254]
2 68 ms 49 ms 55 ms lo0-plusnet.pte-ag2.plus.net [195.166.128.72]
3 72 ms 48 ms 66 ms ge0-0-0-504.pte-gw1.plus.net [84.92.4.89]
4 64 ms 52 ms 48 ms te2-2.pcl-gw01.plus.net [212.159.0.185]
5 30 ms 233 ms 30 ms vl63.pcl-lb01.plus.net [212.159.2.252]
6 271 ms 281 ms 60 ms pth-cdns02.plus.net [212.159.13.50]
Trace complete.

Finally try performing a DNS lookup against each of the DNS addresses using a command line utility like 'nslookup'
Quote
C:\Users\admin>nslookup bbc.co.uk 212.159.13.49
Server: pth-cdns01.plus.net
Address: 212.159.13.49
Non-authoritative answer:
Name: bbc.co.uk
Address: 212.58.254.252

Quote
C:\Users\admin>nslookup bbc.co.uk 212.159.13.50
Server: pth-cdns02.plus.net
Address: 212.159.13.50
Non-authoritative answer:
Name: bbc.co.uk
Address: 212.58.254.252

Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵

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Community Veteran
Posts: 38,460
Thanks: 1,033
Fixes: 62
Registered: ‎15-06-2007

Re: DNS weirdness

Lookup failure to maps.google.co.uk (retry fixed it) and  Google Earth reports network failure (after running the tracerts it worked)
C:\Users\James>tracert 212.159.13.49
Tracing route to 212.159.13.49 over a maximum of 30 hops
  1    <1 ms    <1 ms    <1 ms  192.168.0.1
  2    42 ms    41 ms    36 ms  195.166.128.53
  3    42 ms    39 ms    40 ms  84.92.3.93
  4    39 ms    48 ms    44 ms  212.159.2.124
  5    49 ms    45 ms    54 ms  pth-cdns01.plus.net [212.159.13.49]
Trace complete.
C:\Users\James>tracert 212.159.13.50
Tracing route to 212.159.13.50 over a maximum of 30 hops
  1    <1 ms    <1 ms    <1 ms  192.168.0.1
  2    59 ms    40 ms    42 ms  lo0-plusnet.ptn-ag2.plus.net [195.166.128.53]
  3   207 ms    47 ms   179 ms  gi2-2-204.ptn-gw02.plus.net [84.92.3.93]
  4    47 ms    45 ms    44 ms  vl55.ptn-lb01.plus.net [212.159.2.124]
  5    39 ms    38 ms    41 ms  pth-cdns02.plus.net [212.159.13.50]
Trace complete.
Two things - the tracert was appallingly slow and what happened on the first one
NSlookup worked fine
Ran tracerts again - no problem - speeds back to normal
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Community Veteran
Posts: 38,460
Thanks: 1,033
Fixes: 62
Registered: ‎15-06-2007

Re: DNS weirdness

I am now getting multiple failures - now switched back to the automatic ones 212.159.6.10  212.159.6.9 and it seems to have improved
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Grafter
Posts: 623
Thanks: 3
Registered: ‎01-08-2007

Re: DNS weirdness

Still getting this.  Intermittent lookup errors on Google, BBC and here.  This is happening with both the OpenDNS and the  Plusnet servers.  To tell the truth it's beginning to really get on my nerves as nearly everything I'm attempting to do needs an internet connection.  Hell, I can't even play WoW to relieve some tension.
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Dabbler
Posts: 24
Registered: ‎22-11-2007

Re: DNS weirdness

Still playing up and has been like it most of the day on and off. Just had to reset my router to alternativve DNS address again to connect properly.
Interesting that I was still able to download from a site already connected too while not being able to resolve any new sites within my web browser!
Surely Plusnet must realise there IS a problem?
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Community Veteran
Posts: 1,136
Thanks: 2
Registered: ‎30-07-2007

Re: DNS weirdness

Same, seeing intermittent slowness resolving hosts.
Configured my router to use all 4 servers and fall back to querying the root servers if all else fails.
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)
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Community Veteran
Posts: 38,460
Thanks: 1,033
Fixes: 62
Registered: ‎15-06-2007

Re: DNS weirdness

I have given up - I am sick of the Plusnet DNS servers - now using OpenDNS and everything is much faster and reliable
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Moderator
Moderator
Posts: 24,040
Thanks: 4,226
Fixes: 1,081
Registered: ‎11-01-2008

Re: DNS weirdness

I haven't used the PN DNS servers for about 8 months now..
Customer / Moderator
If it helped click the thumb
If it fixed it click 'This fixed my problem'
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Grafter
Posts: 96
Registered: ‎15-06-2007

Re: DNS weirdness

I have noticed this problem last night and again tonight. Have rebooted the router a few times hoping it would disappear
Just now wondering if it  is probably the reason why I also cannot buy a map from TomTom which I have been trying to do for the last few days since Sunday with different failures and they told me nothing was wrong and I have (unfortunately  Embarrassed ) sent them a stinking email saying it is their servers!!! Embarrassed
Tonight it as bad as it was last night. I have just blamed my son and made him switch his laptop off as I couldn't even download an update from Malwarebytes as I thought it might be malware. Can't  open up pages such as TomTom home page, google and even plusnet. Rebooting the router fixes it for a short time and then it starts to fail again.
It is absolutely unusable as it stands.
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Community Veteran
Posts: 1,887
Thanks: 5
Registered: ‎05-04-2007

Re: DNS weirdness

You're not wrong Jim - the servers were at best, flaky with loads of 404 errors on a regular basis, so like you, I went over to the OpenDNS service and it has been fine ever since.
Edit: If like me you're fed up with the flaky servers, use these ones for OpenDNS: - 208.67.222.222 208.67.220.220

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Grafter
Posts: 204
Registered: ‎07-08-2007

Re: DNS weirdness

was going to switch to openDNS - but running traces to both is currently throwing up some BIG numbers... any other suggestions?
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Community Veteran
Posts: 1,136
Thanks: 2
Registered: ‎30-07-2007

Re: DNS weirdness

Quote
[adw@skynet ~]$ script
Script started, output file is typescript
[adw@skynet ~]$ cat /etc/resolv.conf
search avatastic.co.uk
nameserver 212.159.6.10
nameserver 212.159.6.9
nameserver 212.159.13.49
nameserver 212.159.13.50
nameserver 10.0.1.1
[adw@skynet ~]$ traceroute 212.159.6.10
traceroute to 212.159.6.10 (212.159.6.10), 64 hops max, 52 byte packets
1  lo0-plusnet.pte-ag2.plus.net (195.166.128.72)  44.558 ms  35.781 ms  33.525 ms
2  ge0-0-0-504.pte-gw1.plus.net (84.92.4.89)  32.009 ms  33.421 ms  34.444 ms
3  te2-2.pcl-gw01.plus.net (212.159.0.185)  32.592 ms  35.813 ms  46.553 ms
4  * * *
5  * * *
6  * * *
^C
[adw@skynet ~]$ traceroute 212.159.6.9
traceroute to 212.159.6.9 (212.159.6.9), 64 hops max, 52 byte packets
1  lo0-plusnet.pte-ag2.plus.net (195.166.128.72)  43.544 ms  34.813 ms  41.876 ms
2  ge0-0-0-504.pte-gw1.plus.net (84.92.4.89)  36.027 ms  36.631 ms  34.951 ms
3  te2-2.pcl-gw01.plus.net (212.159.0.185)  43.899 ms  35.356 ms  34.980 ms
4  * * *
5  * * *
6  * * *
^C
[adw@skynet ~]$ traceroute 212.159.13.49
traceroute to 212.159.13.49 (212.159.13.49), 64 hops max, 52 byte packets
1  lo0-plusnet.pte-ag2.plus.net (195.166.128.72)  40.569 ms  37.281 ms  38.240 ms
2  ge0-0-0-504.pte-gw1.plus.net (84.92.4.89)  33.981 ms  35.896 ms  34.923 ms
3  te2-2.pcl-gw01.plus.net (212.159.0.185)  33.059 ms  38.365 ms  52.488 ms
4  * * *
5  * * *
6  * * *
^C
[adw@skynet ~]$ traceroute 212.159.13.50
traceroute to 212.159.13.50 (212.159.13.50), 64 hops max, 52 byte packets
1  lo0-plusnet.pte-ag2.plus.net (195.166.128.72)  36.174 ms  33.332 ms  34.509 ms
2  ge0-0-0-504.pte-gw1.plus.net (84.92.4.89)  36.023 ms  40.840 ms  36.701 ms
3  te2-2.pcl-gw01.plus.net (212.159.0.185)  35.932 ms  38.286 ms  42.659 ms
4  * * *
5  * * *
6  * * *
^C
[adw@skynet ~]$ exit
Script done, output file is typescript

Looks like there is something down somewhere ...
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)
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Grafter
Posts: 96
Registered: ‎15-06-2007

Re: DNS weirdness

Have just tried OpenDNS and no better  Angry
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Community Veteran
Posts: 1,887
Thanks: 5
Registered: ‎05-04-2007

Re: DNS weirdness

tried flushing your local DNS cache?
ipconfig /flushdns