Reverse DNS problems
 

OK, this is relayed via a friend, any ideas on this?

"As you may already know I'm having problems with reverse DNS over here - Demon are reverse mappinng all of our IP addresses (and I assume everyone else's address) to a generic "no-dns-yet.demon.co.uk" entry. I can't believe this is "legal", but I can't for the life of me find anywhere which says what you are officially supposed to do with IP addresses that don't have a real host name.

Any thoughts, or good web resources spring to mind?"



They have Demon coming back to them, and they want to be able to have something that shows what they are doing is wrong (not in a legal sense but in a technical sense) and why they should not be doing it.

Any sites or info you can point me and then I him, at?

Thank you kindly.

Some software when receiving a connection will perform a reverse lookup to try and determine if the connection is being spoofed. If the forward and reverse lookup are not the same the connection will be dropped. May be documented on the sendmail site.

WTF ?

As the RIPE registered owner of IP addresses, Demon can do what it likes with the reverse entries for them. All Responsible ISPs would add generic host names for them.

If the IP addresses are fixed and allocated I'm sure demon will change them to then to the actual reverse DNS if required.

For goodness sake dont think though that by removing a generic reverse DSN entry yu'll be mor secure or any such nonsense.

Dean