IPv6 and nameservers

interfasys

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Just a heads up that it's apparently a bad idea to have both a A and a AAAA record for a nameserver.
Some mail providers like Hotmail will not find your domains anymore...
 

nobaloney

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Can you explain what you mean?

Do you mean that you can't have a nameserver which has both an A record and an AAAA record assigned to it?

For example, an A record finds a nameserver, and an AAAA record finds the same nameserver?

Or do you mean something else?

Can you supply some example, and let us know how you determined this?

Thanks.

Jeff
 

interfasys

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Do you mean that you can't have a nameserver which has both an A record and an AAAA record assigned to it?
Yes, apparently, it's a bad idea.
I have no idea why. All my tests returned the correct information, using various locations and networks, but Hotmail doesn't get the A record apparently.
 

nobaloney

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How can you tell that's the problem?

Can you have (for example)

ns1.nameserver.example.com with an A record and ns16.nameserver.example.com with an AAAA record, but both the same machine/nameserver?

Did you find this by your own tests, or read something? If the latter, please post a link.

Thanks!

Jeff
 

interfasys

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Because the second I deleted the AAAA record, the server got flooded with emails that were in the queue on Hotmail's servers.

You're welcome to do your own experiment and share the results :)
 

nobaloney

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Was it simply an AAAA record pointing to the nameserver hosting the domain? Or some other AAAA record? That's what I'm trying to understand.

Thanks!

Jeff
 

nobaloney

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Thanks. Very interesting. I wonder how Hotmail can even tell if there's an AAAA record for a nameserver it's looking up by A record.

Have you attempted to ask the folk at http://postmaster.hotmail.com? Note it's not as easy as it once was to use; you need a one-use code to sign in with if you don't have a hotmail account.

Jeff
 

interfasys

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My guess is that they have a system that is partially IPv6 ready and they don't know what to do with the reply they get. I remember having read somewehere that it was best to create separate nameservers for IPv6, but I didn't do any more research since then.
Another ISP that had problems is Hurricane Electric, but they are a tunnel broker, so maybe they got confused as well.
It could be a misconfiguration somewhere, but Gmail and lots of other senders were working fine, so it's difficult to try and guess what exactly was the problem.
We also ran lots of DNS reports, all saying that things were fine, showinf us both the A and AAAA record.
All I know is that the fix was as simple as removing the AAAA record, so I thought I would post it here, in case someone notices the same problem and is looking for a solution.

Regarding contacting Hotmail, there doesn't seem to be an easy way. I only found one form that deals with email blocking when sending to hotmail, but we didn't have that problem, we could send to everybody.
 

nobaloney

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Another ISP that had problems is Hurricane Electric, but they are a tunnel broker, so maybe they got confused as well.
Do you have any links to this? I'm concerned because our only provider offering us tunnelling (which we'll all need as we begin to offer IPv6) is HE.
Regarding contacting Hotmail, there doesn't seem to be an easy way. I only found one form that deals with email blocking when sending to hotmail, but we didn't have that problem, we could send to everybody.
I notice this now; the entire postmaster.hotmail.com site is gone :(.

Jeff
 
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