cancel
Showing results for 
Search instead for 
Did you mean: 

DNS root servers blocked?

FIXED
jamiecon
Newbie
Posts: 4
Thanks: 2
Registered: ‎18-10-2022

DNS root servers blocked?

Hi all,

I am attempting to debug a DNS issue by tracing a DNS query through the hierarchy. However, it appears that some DNS servers are blocked on Plusnet.

For example:

Resolve-DnsName com. -Type NS -Server m.root-servers.net
Resolve-DnsName: com. : DNS server failure.

Can anyone confirm that this is the case?

Many thanks

10 REPLIES 10
Baldrick1
Moderator
Moderator
Posts: 12,379
Thanks: 5,559
Fixes: 430
Registered: ‎30-06-2016

Re: DNS root servers blocked?


Moderators Note


This topic has been moved from Broadband to Everything Else 

Moderator and Customer
If this helped - select the Thumb
If it fixed it,  help others - select 'This Fixed My Problem'

bobpullen
Community Gaffer
Community Gaffer
Posts: 16,930
Thanks: 5,016
Fixes: 317
Registered: ‎04-04-2007

Re: DNS root servers blocked?

I run an Unbound instance on my Plusnet connection without issue, so the root servers definitely aren't blocked in my case.

I also don't see what you do: -

~$ dig com. ns @m.root-servers.net

; <<>> DiG 9.16.33-Debian <<>> com. ns @m.root-servers.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37900
;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;com.                           IN      NS

;; ANSWER SECTION:
com.                    85862   IN      NS      f.gtld-servers.net.
com.                    85862   IN      NS      j.gtld-servers.net.
com.                    85862   IN      NS      g.gtld-servers.net.
com.                    85862   IN      NS      i.gtld-servers.net.
com.                    85862   IN      NS      b.gtld-servers.net.
com.                    85862   IN      NS      a.gtld-servers.net.
com.                    85862   IN      NS      c.gtld-servers.net.
com.                    85862   IN      NS      m.gtld-servers.net.
com.                    85862   IN      NS      l.gtld-servers.net.
com.                    85862   IN      NS      h.gtld-servers.net.
com.                    85862   IN      NS      d.gtld-servers.net.
com.                    85862   IN      NS      k.gtld-servers.net.
com.                    85862   IN      NS      e.gtld-servers.net.

;; Query time: 19 msec
;; SERVER: 202.12.27.33#53(202.12.27.33)
;; WHEN: Tue Oct 18 19:29:56 BST 2022
;; MSG SIZE  rcvd: 256

 

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

jamiecon
Newbie
Posts: 4
Thanks: 2
Registered: ‎18-10-2022

Re: DNS root servers blocked?

Hi Bob,

 

Many thanks for your response. I have success with the same commands from a VM running in Azure, and other machines on my local network have the same issue as my main machine.

Seems like the problem may still be on my end though. There isn't some hidden configuration option on the PlusNet router or something perhaps?

 

Regards,

 

Jamie

bobpullen
Community Gaffer
Community Gaffer
Posts: 16,930
Thanks: 5,016
Fixes: 317
Registered: ‎04-04-2007

Re: DNS root servers blocked?

Nothing I'm aware of Jamie.

My set-up is known to work with both a Hub One and Hub Two although worth noting that I don't tend to use the hubs DHCP server. I have that disabled and it's looked after elsewhere in my network.

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

seebee
Aspiring Pro
Posts: 107
Thanks: 80
Fixes: 9
Registered: ‎08-07-2017

Re: DNS root servers blocked?

Fix

Is it a problem with the "Resolve-DnsName" command? This link seems to show others get this problem:

Unexpected exception returned from cmdlet Resolve-DNSName - Microsoft Q&A

I see the same error in windows as @jamiecon sees, but dig on linux works fine, like @bobpullen sees.

bobpullen
Community Gaffer
Community Gaffer
Posts: 16,930
Thanks: 5,016
Fixes: 317
Registered: ‎04-04-2007

Re: DNS root servers blocked?

Interesting. The Powershell command also works fine for me Win 11: -

PS C:\Users\Bob> Resolve-DnsName com. -Type NS -Server m.root-servers.net

Name                           Type   TTL   Section    NameHost
----                           ----   ---   -------    --------
com                            NS     86400 Answer     k.gtld-servers.net
com                            NS     86400 Answer     g.gtld-servers.net
com                            NS     86400 Answer     b.gtld-servers.net
com                            NS     86400 Answer     i.gtld-servers.net
com                            NS     86400 Answer     m.gtld-servers.net
com                            NS     86400 Answer     d.gtld-servers.net
com                            NS     86400 Answer     c.gtld-servers.net
com                            NS     86400 Answer     h.gtld-servers.net
com                            NS     86400 Answer     a.gtld-servers.net
com                            NS     86400 Answer     l.gtld-servers.net
com                            NS     86400 Answer     f.gtld-servers.net
com                            NS     86400 Answer     e.gtld-servers.net
com                            NS     86400 Answer     j.gtld-servers.net

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

jamiecon
Newbie
Posts: 4
Thanks: 2
Registered: ‎18-10-2022

Re: DNS root servers blocked?

Hi both,

Just looked at the traffic in Wireshark and the post that @seebee links to is correct - the response is coming back but is not being correctly displayed by the Resolve-DnsName cmdlet.

I am also running Win11, fully updated and pretty much default configuration. The error occurs for me in both PowerShell Core and Windows PowerShell, although there is more error detail in Windows PowerShell:

PS C:\Users\jamie> Resolve-DnsName com. -Type NS -Server m.root-servers.net
Resolve-DnsName : com. : DNS server failure
At line:1 char:1
+ Resolve-DnsName com. -Type NS -Server m.root-servers.net
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ResourceUnavailable: (com.:String) [Resolve-DnsName], Win32Exception
    + FullyQualifiedErrorId : RCODE_SERVER_FAILURE,Microsoft.DnsClient.Commands.ResolveDnsName

@bobpullenreally interesting that you are successful with the same command. Can't really explain that one - but if it's dependent on some configuration characteristic it might explain why the bug hasn't been squashed?

Appreciate everyone's help on this. If anyone's curious happy to do some more digging but otherwise I guess we can consider the matter closed! PlusNet - not guilty 🙂

Regards,

Jamie

Brynow
Hooked
Posts: 5
Registered: ‎14-12-2021

Re: DNS root servers blocked?

Hi, could this issue be why my Screwfix app Checkout has stopped working when I'm on my Plusnet WiFi?  When I try to  checkout I get this error: 

Domain: undefined

Error code: -2

Description: ERR_NAME_NOT_RESOLVED

This was working OK a couple of weeks ago, and it still works OK when I'm on the mobile network.

jamiecon
Newbie
Posts: 4
Thanks: 2
Registered: ‎18-10-2022

Re: DNS root servers blocked?

Hey Brynow,

 

Unrelated I'm afraid. Your error is probably transient (likely) or a bug in the Screwfix app (less likely if it works on mobile).

Make sure your app's fully updated and maybe give it a day or two.

 

Cheers,

 

Jamie

bobpullen
Community Gaffer
Community Gaffer
Posts: 16,930
Thanks: 5,016
Fixes: 317
Registered: ‎04-04-2007

Re: DNS root servers blocked?

@Brynow - your problem is related to this.

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