Kitz Forum

Computers & Hardware => Networking => Topic started by: Weaver on January 20, 2018, 07:26:14 AM

Title: DNS weirdness with one PTR lookup
Post by: Weaver on January 20, 2018, 07:26:14 AM
What have I done wrong? If you do a ptr lookup in the dns for 81.187.xxx.201 all is well, same is true for 81.187.xxx.199, but not 81.187.xxx.200? Tried it from more than one dns server too.

- update : the ptr records are supposed to be defined on AA.net.uk’s servers. I can't set ptr records myself on my own server, it's a hosted dns server provided by ukservers ltd (virtualnames), and for some reason it doesn't support entering ptr records, just A / AAAA / CNAME / MX / TXT / SPF etc. - the usual cast.

On AA’s server ‘clueless.aa.net.uk’ I deleted the ptr record and added it back. It now seems to be visible. What on earth?
Title: Re: DNS weirdness with one PTR lookup
Post by: d2d4j on January 20, 2018, 09:52:41 AM
Hi weaver

I hope you don’t mind, but you may want to insure your ip addresses shown

This may save you bandwidth from probing eyes now you have shown them

I think it may just be a cron job run timing as changes are not instant. However, as I do not use nor have any idea how AA are setup for dns, then I could be wrong sorry but usually dns changes go into a cron job queue to be actioned (this may just be from master to slaves, and you initial test may have used the secondary dns server)

It could also be stale dns cache as your TTL is high on primary but low on secondary

Many thanks

John
Title: Re: DNS weirdness with one PTR lookup
Post by: d2d4j on January 20, 2018, 09:56:21 AM
Sorry, iPhone changing text

It should read obscure ip addresses

Many thanks

John
Title: Re: DNS weirdness with one PTR lookup
Post by: Weaver on January 20, 2018, 10:15:38 AM
@d2d4j indeed, took your advice and hid a byte. Nuisances could happen.