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Re: DNS issue affecting (and subdomains)

From: Sebastian Tennant
Subject: Re: DNS issue affecting (and subdomains)
Date: Sun, 26 Mar 2023 16:47:34 +0000
User-agent: Gnus/5.13 (Gnus v5.13)

Quoth Ar Rakin <>
on Sat, 25 Mar 2023 23:38:29 +0600:
> Hello Sebastian,
> I'm also unable to access I don't exactly know why this is
> happening, though I've encountered this type of issues before, with
> my own domains. But it got fixed automatically after a few
> days. Hopefully, it will be fixed automatically after some time.
> What I can see:
> $ host
> ;; connection timed out; no servers could be reached
> $ ping
> ping: Temporary failure in name resolution
> Thanks,
> Rakin

Hello Rakin.  Thanks for the corroboration.

Quoth Eli Zaretskii <>
on Sat, 25 Mar 2023 20:52:00 +0300:
>> […]
> You will find the information here:
> That place is always good to look at when such issues occur.

Hello Eli.  Thanks for the link.  Noted.

Quoth Bob Proulx <>
on Sat, 25 Mar 2023 15:05:44 -0600:
>> […]
> +1 for the status page.  The FSF
> sysadmins post information there (sometimes terse) when there are
> problems seen that affect systems.  It's something everyone should
> bookmark where they can find it easily.
>>  $ host
>>  [...]
>>  Host not found: 2(SERVFAIL)
>> Nope, Google's resolver can't resolve either.
> The authoritative nameservers (a fancy title for the upstream ones)
> are getting DDoS'd off the net.  Which means that all resolution by
> downstream nameservers, even Google ones, are timing out.

Hello Bob.  A DDoS attack.  I see.

> Compounded by the very short 300 second TTL on the records
> mean that even if a lookup is successful that it can only be cached
> for five minutes and then discarded.  Upon which then it needs to be
> looked up again and the query will have to fight its way through the
> DDoS in a mixed martial arts cage fight arena to get the data again.

What's the thinking behind the short TTL?

>> […]
> The nameservers are overwhelmed making them slow to respond.  And
> then additionally I am seeing a very high packet loss across the
> network into the Boston machines.  That high packet loss means
> retries at the network protocol level making things slow.  I have
> seen 30-45 seconds on average here looking up DNS for a while.


>> […]
> There is really nothing special about the Google resolver.  If the
> upstream ns* nameservers can't receive and can't send data
> then names cannot be resolved.

Yup.  Understood.  I know there's nothing special about Google's
nameservers.  They have an easy-to-remember IP address, that's all.

>> I fetch from every 30 minutes and the fetch beagn to
>> fail two days ago (on 23rd March) at around 10pm GMT.  It has been
>> failing much more often than not since then.

> Yes.  That's about when the attack started.  I assume it is an
> attack.  That's what sysadmin said about it.  I have no special
> ability to observe this particular attack and am suffering through
> the packet loss of it along with the rest of you.

:-) It seems the worst is over now.  (Until the next time, in any

Quoth Ian Kelling <>
on Sat, 25 Mar 2023 18:51:48 -0400:
> Update: We think we've got things working now.

Hello Ian.  Thanks for the update.  And for your efforts restoring
normal service.

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