topic Re: DNS root servers blocked? in Everything else

DNS root servers blocked?

jamiecon — Tue, 18 Oct 2022 08:41:34 GMT

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

Re: DNS root servers blocked?

Baldrick1 — Tue, 18 Oct 2022 09:04:00 GMT

Moderators Note

This topic has been moved from Broadband to Everything Else

Re: DNS root servers blocked?

bobpullen — Tue, 18 Oct 2022 18:31:13 GMT

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

Re: DNS root servers blocked?

jamiecon — Wed, 19 Oct 2022 12:01:09 GMT

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

Re: DNS root servers blocked?

bobpullen — Wed, 19 Oct 2022 12:47:54 GMT

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.

Re: DNS root servers blocked?

seebee — Wed, 19 Oct 2022 13:23:38 GMT

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.

Re: DNS root servers blocked?

bobpullen — Wed, 19 Oct 2022 13:31:28 GMT

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

Re: DNS root servers blocked?

jamiecon — Wed, 19 Oct 2022 13:56:17 GMT

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

Re: DNS root servers blocked?

Brynow — Wed, 02 Nov 2022 16:05:28 GMT

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.

Re: DNS root servers blocked?

jamiecon — Wed, 02 Nov 2022 17:13:40 GMT

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

Re: DNS root servers blocked?

bobpullen — Wed, 02 Nov 2022 20:57:26 GMT

@Brynow - your problem is related to this.