4.3.2.1.dyn.plus.net instead of 1.2.3.4.plus.net

[#1]

Confused ?

I'm interested why some plusnet addresses appear as 4.3.2.1.dyn.plus.net instead of 1.2.3.4.plus.net and other appear as 1.2.3.4.plus.net which is the expected address.

In other words, why is the ip address before the plus.net reversed and dyn added inbetween while others are not reversed before the plus.net nor do they have dyn added.

Perhaps some are fixed ip addresses and others are not ?

Regards..

[#2]

@C1Rider 

I understand that the Dyn indicates a dynamic address. Are you sure that these are reversed? They come from a totally different pool of addresses to the static ones.

Your second example is a static address.

[#3]

Yes, the 4 dot address is reversed.

It was during the last week that the dynamic changed from being the same as a static address.

Regards..

[#4]

rDNS for dynamic IP's is <ip address>.dyn.plus,net with the octets reversed and separated by '.'

rDNS for static IP's by default is <accountname>.plus.com , if the anonomised ip format is requested it is <ip address>.plus.com with the octets reversed and separated by '-'

[#5]

If I use the host cmd 1.2.3.4 on a static address I get :-

4.3.2.1.in-addr.arpa domain name pointer 1.2.3.4.plus.com.

Last week I got the same with a dynamic address.

This week using the host cmd 1.2.3.4 on a dynamic address I get :-

4.3.2.1.in-addr.arpa domain name pointer 4.3.2.1.dyn.plus.net.

So the info on a dynamic address now shows it reversed two times when previously it was reversed once, in the same manner as a static address.

Also if I use the host cmd 4.3.2.1.dyn.plus.net I get:-

1.2.3.4

All very confusing !

Regards..

[#6]

The IP address being reversed in a PTR record is fairly common practice. See here.

[#7]

I have read through the info in the link --thanks.

My original query has been confirmed in that if [ dyn ] is included then the address is dynamic, if not, it's static, although both were the same the previous week.

Comparing Plusnet to BT shows this difference :-

4.3.2.1.in-addr.arpa domain name pointer 4.3.2.1.dyn.plus.net.

4.3.2.1.in-addr.arpa domain name pointer host1-2-3-4.range86-185.btcentralplus.com.

Still curious !

Regards..