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sukh187
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DNS Issues since outage

Hi all I wonder if someone can help, I suffered an area outage on Wednesday 20th Jan 2021 in my area (DA11), this was for BB and TV, service resumed the following day, but for the last week I've experienced really slow web browsing on all my devices whether wired or wireless. I did the usual checks of restarting the router etc.

After a period of diagnosis I've worked out the issue, as the title suggests DNS.

I have my devices set to use cloudfare DNS, 1.1.1.1 - this is set on the devices as I use the SH3 as modem and router. Speed from the service is as expected - 100mb.

When I reverted back to using VM DNS services the pages load instantly, I then checked by changing to other cloud provider such as google, 8.8.8.8 and browsing was slow again. This was not the case before the service outage so expect some routing has gone amiss.

Who can I speak to in VM to get this sorted the 1st level tech guys are going through the normal restart everything set back to factory settings. 

Thanks in advance

Sukh

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tehwolf
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Re: DNS Issues since outage

Weird.

When you have your dns configured to use google/cloud flare, what happens when you open a command prompt and use nslookup?

To test, open a command prompt, type nslookup and hit enter... you should get a new > prompt. Above the > prompt it should say default server 8.8.8.8 or something similar.. then just type in a dns name and hit enter - does it time out, does it come back instantly, what happens?

 

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sukh187
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Re: DNS Issues since outage

Hi tehwolf , using nslookup I receive a resolution to any dns servers and websites, as the pages do subsequently load its more of a routing issue (i.e. taking too long) I also did some traceroutes to 1.1.1.1 and 8.8.8.8 both see timeouts along the hops. I can post these to see if others see similar.

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tehwolf
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Re: DNS Issues since outage

* * * in a traceroute isn’t relevant - it just means that hte device that the traffic is passing through doesn’t respond to ICMP packets - this can be ignored.

when you were using nslookup, did you experience the delay in lookups? And did you confirm that the default server was either a google or cloudflare one?

 

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sukh187
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Re: DNS Issues since outage

Tracing route to one.one.one.one [1.1.1.1]
over a maximum of 30 hops:

1 2 ms 2 ms 1 ms 192.168.0.1
2 10 ms 9 ms 9 ms 10.53.35.241
3 9 ms 15 ms 9 ms basl-core-2b-xe-815-0.network.virginmedia.net [80.1.81.113]
4 * * * Request timed out.
5 * * * Request timed out.
6 * * * Request timed out.
7 19 ms 18 ms 17 ms 86.85-254-62.static.virginmediabusiness.co.uk [62.254.85.86]
8 18 ms 16 ms 17 ms ldn-b1-link.telia.net [213.248.84.25]
9 26 ms 30 ms 20 ms ldn-bb4-link.ip.twelve99.net [62.115.122.180]
10 31 ms 26 ms 33 ms dln-b2-link.ip.twelve99.net [62.115.120.105]
11 27 ms 31 ms 29 ms cloudflare-ic-310815-dln-b2.c.telia.net [62.115.55.14]
12 28 ms 27 ms 26 ms one.one.one.one [1.1.1.1]

Trace complete.
PS C:\WINDOWS\system32> tracert 8.8.8.8

Tracing route to dns.google [8.8.8.8]
over a maximum of 30 hops:

1 2 ms 2 ms 1 ms 192.168.0.1
2 13 ms 9 ms 7 ms 10.53.35.241
3 11 ms 9 ms 9 ms basl-core-2b-xe-716-0.network.virginmedia.net [62.252.229.185]
4 * * * Request timed out.
5 15 ms 17 ms 17 ms eislou2-ic-1-ae3-0.network.virginmedia.net [62.254.85.145]
6 22 ms 17 ms 16 ms 6-14-250-212.static.virginm.net [212.250.14.6]
7 21 ms 21 ms 20 ms 216.239.40.71
8 17 ms 15 ms 21 ms 108.170.232.105
9 18 ms 17 ms 21 ms dns.google [8.8.8.8]

Trace complete.
PS C:\WINDOWS\system32> tracert 194.168.4.100

Tracing route to cache1.service.virginmedia.net [194.168.4.100]
over a maximum of 30 hops:

1 1 ms 2 ms 1 ms 192.168.0.1
2 12 ms 11 ms 16 ms 10.53.35.241
3 29 ms 16 ms 17 ms basl-core-2b-xe-716-0.network.virginmedia.net [62.252.229.185]
4 9 ms 17 ms 7 ms cache1.service.virginmedia.net [194.168.4.100]

Trace complete.
PS C:\WINDOWS\system32>
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sukh187
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Re: DNS Issues since outage

Let me get this for you

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sukh187
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Re: DNS Issues since outage

Responses come back instantly

PS C:\WINDOWS\system32> nslookup
Default Server: one.one.one.one
Address: 1.1.1.1

> 1.1.1.1
Server: one.one.one.one
Address: 1.1.1.1

Name: one.one.one.one
Address: 1.1.1.1

> www.bbc.co.uk
Server: one.one.one.one
Address: 1.1.1.1

Non-authoritative answer:
Name: bbc.map.fastly.net
Addresses: 151.101.0.81
151.101.64.81
151.101.128.81
151.101.192.81
Aliases: www.bbc.co.uk
www.bbc.net.uk

> 8.8.8.8
Server: one.one.one.one
Address: 1.1.1.1

Name: dns.google
Address: 8.8.8.8
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tehwolf
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Re: DNS Issues since outage

So, the nslookup shows that there’s no issue between you and the name servers you’re trying to use..

My windows knowledge is a bit rusty, but AFAIK the only difference between nslookup and your browser doing a lookup is that nslookup queries the dns server directly whereas a “normal” lookup will first check whether the dns name is the computers own name, then it will check the hosts file, then it will query the dns server

my knee jerk would be a device issue, but you say it’s affecting all of the devices on your network? What other devices is it affecting?

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sukh187
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Re: DNS Issues since outage

I have a couple of other laptops that we use to browse where I have set the DNS to something other than VMs all affected.

When using VMs DNS all is fine and pages load instantly

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tehwolf
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Re: DNS Issues since outage

What about on phones etc? If you manually configure a phone to use 8.8.8.8 does it also suffer delays when browsing the web?

 

 

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