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DNS weirdness

GrahamC
Grafter
Posts: 257
Registered: ‎19-07-2009

Re: DNS weirdness

Well here's another James...
lost the lookup ability at around 7pm...
C:\Windows\system32>tracert 212.159.13.49
Tracing route to 212.159.13.49 over a maximum of 30 hops
  1    <1 ms    18 ms    <1 ms  192.168.1.1
  2    57 ms    49 ms    42 ms  195.166.128.39
  3    42 ms    51 ms    44 ms  84.92.0.141
  4    49 ms    41 ms    47 ms  212.159.2.252
  5    42 ms    40 ms    40 ms  212.159.13.49
Trace complete.
C:\Windows\system32>tracert 212.159.13.50
Tracing route to 212.159.13.50 over a maximum of 30 hops
  1    <1 ms    11 ms    <1 ms  192.168.1.1
  2    46 ms    49 ms    40 ms  195.166.128.39
  3    61 ms    57 ms    50 ms  84.92.0.141
  4    51 ms    41 ms    40 ms  212.159.2.252
  5    65 ms    42 ms    48 ms  212.159.13.50
Trace complete.
C:\Windows\system32>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:  212.58.224.138

C:\Windows\system32>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:  212.58.224.138
This has now been happening for several weeks now, each time requiring a re-boot of the router.
adriantribe
Dabbler
Posts: 12
Registered: ‎09-06-2008

Re: DNS weirdness

@jameseh
As previously mentioned, the concern I have about that is that I use three
different connectivity providers with my laptop, PlusNet while at home,
3 mobile while travelling (as I am right now), and my wolrk network once
I'm at work.  It was suggested a while back that hard-coding the DNS
server details into my laptop rather than on my home router might
cause issues with those other connections.
jelv
Seasoned Hero
Posts: 26,785
Thanks: 971
Fixes: 10
Registered: ‎10-04-2007

Re: DNS weirdness

Can you reconfigure your router to add an OpenDNS server as well as a PN DNS server?
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£14.40/month)
Mobile: iD mobile (£4/month)
GrahamC
Grafter
Posts: 257
Registered: ‎19-07-2009

Re: DNS weirdness

And again.... 10pm tonight
C:\Windows\system32>tracert 212.159.13.49
Tracing route to 212.159.13.49 over a maximum of 30 hops
  1    <1 ms    <1 ms    19 ms  192.168.1.1
  2    59 ms    46 ms    40 ms  195.166.128.134
  3    45 ms    44 ms    71 ms  84.92.0.229
  4    43 ms    53 ms    51 ms  212.159.2.252
  5    40 ms    40 ms    38 ms  212.159.13.49
Trace complete.
C:\Windows\system32>tracert 212.159.13.50
Tracing route to 212.159.13.50 over a maximum of 30 hops
  1    <1 ms    14 ms    <1 ms  192.168.1.1
  2    42 ms    40 ms    63 ms  195.166.128.134
  3    42 ms    40 ms    51 ms  84.92.0.229
  4    45 ms    52 ms    45 ms  212.159.2.252
  5    44 ms    41 ms    43 ms  212.159.13.50
Trace complete.
C:\Windows\system32>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:  212.58.224.138

C:\Windows\system32>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:  212.58.224.138
Router reboot and fine until the next time.
bobpullen
Community Gaffer
Community Gaffer
Posts: 16,869
Thanks: 4,950
Fixes: 315
Registered: ‎04-04-2007

Re: DNS weirdness

Quote from: dannykos
@ Bob – still haven't managed to get a proper trace to run:
traceroute to 212.159.6.10 (212.159.6.10), 64 hops max, 40 byte packets
1  192.168.0.1 (192.168.0.1)  1.686 ms  11.055 ms  11.055 ms
2  lo0.plusnet.thn-ag2.plus.net (195.166.128.93)  31.773 ms *  79.191 ms
3  vl604.thn-gw1.plus.net (84.92.4.169)  26.166 ms  29.630 ms  25.798 ms
4  ae0-102.ptn-gw01.plus.net (212.159.1.53)  97.781 ms  153.601 ms  197.548 ms
5  * * *
6  * * ae0-102.ptn-gw01.plus.net (212.159.1.53)  26.356 ms !X
7  * * *
8  * * *
9  * * *
10  * * *
traceroute to 212.159.6.9 (212.159.6.9), 64 hops max, 40 byte packets
1  * 192.168.0.1 (192.168.0.1)  8.074 ms  1.020 ms
2  lo0.plusnet.thn-ag2.plus.net (195.166.128.93)  26.884 ms  26.701 ms  137.832 ms
3  vl604.thn-gw1.plus.net (84.92.4.169)  35.721 ms  45.878 ms  81.056 ms
4  ae0-102.ptn-gw01.plus.net (212.159.1.53)  27.576 ms  27.196 ms  25.824 ms
5  * * *
6  * * *
7  * * *
8  * * *
9  * * *
10  * * *
maybe it's just something to do with me being on 21CN trial - and on a mac?  I dunno…

Baffling me a bit this one! Undecided Forgive me if you've mentioned it elsewhere in this thread but what router/modem are you using and how's it connected to the MAC?
Quote from: Prod_Man
Hi Bob
Worse than ever today  - very difficult even to access plus net member center.(!)

Thanks for the information Mick.
Quote from: adriantribe
Just had another period of no lookup ability, during which time I did an ipconfig /all.  The relevant part
of the results showed:
Ethernet adapter Wireless Network Connection:
        Connection-specific DNS Suffix  . : home
        Description . . . . . . . . . . . : Intel(R) PRO/Wireless 3945ABG Network Connection
        Physical Address. . . . . . . . . : 00-1F-3C-97-78-99
        Dhcp Enabled. . . . . . . . . . . : Yes
        Autoconfiguration Enabled . . . . : Yes
        IP Address. . . . . . . . . . . . : 192.168.1.2
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . : 192.168.1.1
        DHCP Server . . . . . . . . . . . : 192.168.1.1
        DNS Servers . . . . . . . . . . . : 192.168.1.1
        Lease Obtained. . . . . . . . . . : 17 July 2009 22:35:47
        Lease Expires . . . . . . . . . . : 18 July 2009 22:35:47
So I checked on the router instead, which showed that the DNS servers were set to:
Primary DNS Server 212.159.6.10
Secondary DNS Server 212.159.6.9

As per the discussion between jelv and Oldjim that suggests that your leaving it up to your router to act as a DNS server for your local machines. I'd try specifying your DNS server addresses explicitly in the TCP/IP properties of your network connection.

Quote from: adriantribe
What I don't understand is that during the last problem period I
did an nslookup on, for example, the bbc web site, specifying
the PN DNS server 212.159.6.9 and actually got a result - it was
abe to lookup the name and return the IP address.
However, my web browser was still not able to find the site.

That does sound odd and isn't what I'd expect to see as the result of a DNS problem.
Quote from: GrahamC
Well here's another James...
lost the lookup ability at around 7pm...
C:\Windows\system32>tracert 212.159.13.49
Tracing route to 212.159.13.49 over a maximum of 30 hops
  1    <1 ms    18 ms    <1 ms  192.168.1.1
  2    57 ms    49 ms    42 ms  195.166.128.39
  3    42 ms    51 ms    44 ms  84.92.0.141
  4    49 ms    41 ms    47 ms  212.159.2.252
  5    42 ms    40 ms    40 ms  212.159.13.49
Trace complete.

Another one that baffles me a little due to the previously mentioned fact that their are no host names present in your traces (your NSLOOKUP isn't suggestive of a DNS problem either). Have you tried with a different modem or router to rule hardware out as a potential cause of your issues?
Quote from: adriantribe
As previously mentioned, the concern I have about that is that I use three
different connectivity providers with my laptop, PlusNet while at home,
3 mobile while travelling (as I am right now), and my wolrk network once
I'm at work.  It was suggested a while back that hard-coding the DNS
server details into my laptop rather than on my home router might
cause issues with those other connections.

Jelv's advice makes sense, use 208.67.222.222 as the secondary IP address instead of the one in the screengrab above. That will work from any connection.

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

GrahamC
Grafter
Posts: 257
Registered: ‎19-07-2009

Re: DNS weirdness

Quote from: Bob
Quote from: GrahamC
Well here's another James...
lost the lookup ability at around 7pm...
C:\Windows\system32>tracert 212.159.13.49
Tracing route to 212.159.13.49 over a maximum of 30 hops
  1    <1 ms    18 ms    <1 ms  192.168.1.1
  2    57 ms    49 ms    42 ms  195.166.128.39
  3    42 ms    51 ms    44 ms  84.92.0.141
  4    49 ms    41 ms    47 ms  212.159.2.252
  5    42 ms    40 ms    40 ms  212.159.13.49
Trace complete.

Another one that baffles me a little due to the previously mentioned fact that their are no host names present in your traces (your NSLOOKUP isn't suggestive of a DNS problem either). Have you tried with a different modem or router to rule hardware out as a potential cause of your issues?

Only major change to the system in the last 4 years was an upgrade from XP to VISTA in '07, though the Ethernet driver was updated as below:
Integrated Atheros L1 Gigabit Ethernet on Asus P5K motherboard
Driver Version: 2.4.7.22
Driver Date: 24/04/2009
I've had no outage today, yet, but I have reinstalled my old Voyager 205 (replacing the D-Link G604T) to eliminate the router.
I'll report back in a day or two.
cheers
Graham
dannykos
Grafter
Posts: 204
Registered: ‎07-08-2007

Re: DNS weirdness

@ Bob - i'm currently connected wirelessly on a Netgear DG834GT…
…aside from the strange traces - the connection does just seem a bit sluggish for gaming etc, although actual measured throughput is as expected.
avatastic
Grafter
Posts: 1,136
Thanks: 2
Registered: ‎30-07-2007

Re: DNS weirdness

Quote from: Bob
Quote from: dannykos
@ Bob – still haven't managed to get a proper trace to run:
traceroute to 212.159.6.10 (212.159.6.10), 64 hops max, 40 byte packets
1  192.168.0.1 (192.168.0.1)  1.686 ms  11.055 ms  11.055 ms
2  lo0.plusnet.thn-ag2.plus.net (195.166.128.93)  31.773 ms *  79.191 ms
3  vl604.thn-gw1.plus.net (84.92.4.169)  26.166 ms  29.630 ms  25.798 ms
4  ae0-102.ptn-gw01.plus.net (212.159.1.53)  97.781 ms  153.601 ms  197.548 ms
5  * * *
6  * * ae0-102.ptn-gw01.plus.net (212.159.1.53)  26.356 ms !X
7  * * *
8  * * *
9  * * *
10  * * *
traceroute to 212.159.6.9 (212.159.6.9), 64 hops max, 40 byte packets
1  * 192.168.0.1 (192.168.0.1)  8.074 ms  1.020 ms
2  lo0.plusnet.thn-ag2.plus.net (195.166.128.93)  26.884 ms  26.701 ms  137.832 ms
3  vl604.thn-gw1.plus.net (84.92.4.169)  35.721 ms  45.878 ms  81.056 ms
4  ae0-102.ptn-gw01.plus.net (212.159.1.53)  27.576 ms  27.196 ms  25.824 ms
5  * * *
6  * * *
7  * * *
8  * * *
9  * * *
10  * * *
maybe it's just something to do with me being on 21CN trial - and on a mac?  I dunno…

Baffling me a bit this one! Undecided Forgive me if you've mentioned it elsewhere in this thread but what router/modem are you using and how's it connected to the MAC?

I think I can solve this one!
Linux, BSD and by extension OS X use the UDP method of traceroute, which is dropped by some of PN's hardware along the way.
I verified this by being able to run a tracert on a windows host on my network to the DNS severs which were dropping under FreeBSD.
I was able to work around this by using 'traceroute -I host' (thats an uppercase i not a lower case L).
Quote
for server in 212.159.6.10 212.159.6.9 212.159.13.49 212.159.13.50;do echo "Trace to ${server} began at `date`"; traceroute -I $server; done
Trace to 212.159.6.10 began at Wed Jul 22 09:40:38 BST 2009
traceroute to 212.159.6.10 (212.159.6.10), 64 hops max, 72 byte packets
1  lo0-plusnet.ptn-ag2.plus.net (195.166.128.53)  34.117 ms  33.774 ms  30.021 ms
2  gi2-2-204.ptn-gw02.plus.net (84.92.3.93)  31.139 ms  34.393 ms  33.972 ms
3  vl55.ptn-lb01.plus.net (212.159.2.124)  30.033 ms  34.477 ms  29.825 ms
4  ptn-cdns02.plus.net (212.159.6.10)  29.495 ms  36.085 ms  37.603 ms
Trace to 212.159.6.9 began at Wed Jul 22 09:40:38 BST 2009
traceroute to 212.159.6.9 (212.159.6.9), 64 hops max, 72 byte packets
1  lo0-plusnet.ptn-ag2.plus.net (195.166.128.53)  37.951 ms  35.260 ms  39.150 ms
2  gi2-2-204.ptn-gw02.plus.net (84.92.3.93)  96.301 ms  31.618 ms  47.458 ms
3  vl55.ptn-lb01.plus.net (212.159.2.124)  39.905 ms  35.969 ms  36.148 ms
4  ptn-cdns01.plus.net (212.159.6.9)  35.946 ms  37.050 ms  40.367 ms
Trace to 212.159.13.49 began at Wed Jul 22 09:40:39 BST 2009
traceroute to 212.159.13.49 (212.159.13.49), 64 hops max, 72 byte packets
1  lo0-plusnet.ptn-ag2.plus.net (195.166.128.53)  35.752 ms  34.748 ms  34.440 ms
2  gi2-2-204.ptn-gw02.plus.net (84.92.3.93)  34.968 ms  46.180 ms  33.992 ms
3  vl55.ptn-lb01.plus.net (212.159.2.124)  90.295 ms  35.012 ms  34.920 ms
4  pth-cdns01.plus.net (212.159.13.49)  37.402 ms  33.616 ms  32.932 ms
Trace to 212.159.13.50 began at Wed Jul 22 09:40:39 BST 2009
traceroute to 212.159.13.50 (212.159.13.50), 64 hops max, 72 byte packets
1  lo0-plusnet.ptn-ag2.plus.net (195.166.128.53)  34.905 ms  34.253 ms  39.391 ms
2  gi2-2-204.ptn-gw02.plus.net (84.92.3.93)  48.486 ms  31.114 ms  44.274 ms
3  vl55.ptn-lb01.plus.net (212.159.2.124)  33.490 ms  39.676 ms  33.942 ms
4  pth-cdns02.plus.net (212.159.13.50)  34.943 ms  33.027 ms  35.451 ms

if -I isn't recognised you can try -p icmp or RTFM.
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!)
dannykos
Grafter
Posts: 204
Registered: ‎07-08-2007

Re: DNS weirdness

I think you're onto something there - although none of those extensions worked from terminal for me.  I suppose ultimately it doesn't matter if I can run a trace, as long as the connection is behaving as expected Wink
bobpullen
Community Gaffer
Community Gaffer
Posts: 16,869
Thanks: 4,950
Fixes: 315
Registered: ‎04-04-2007

Re: DNS weirdness

@darkskye that makes sense I guess. I knew about the UDP/ICMP differences as per my post here but I didn't expect this to effect the trace tbh.

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