[dns-wg] request about RIPE vs. ISP and RFC 1921, 2.1

On 15 Oct 2010, at 09:18, thoma spolnik wrote:

> if RIPE assigns an large ip net to an ISP - Does RIPE accept, that  
> this ISP ignores RFC 1921, 2.1 [1] (for commercial interests)?
> Are commercial interests a valid reason [2] for RIPE, that an ISP  
> does not set (generic) PTR records for an used IP?

It's up to the ISP/LIR to decide how to organise the DNS for their  
reverse zones. Though I'm not aware of any policy which explicitly  
states that. Perhaps there should be one. Why not present your ideas  
to this list or even draft a policy proposal?

It might be helpful if you said a bit more about the problem(s) which  
encouraged to to ask these questions.

> Does or does not RIPE claim the compliance with (basic) RFCs (like  
> RFC 1921, 2.1 - I think it is a basic, that every IP must have a  
> correct PTR record.) for assigned IP nets?

To the best of my knowledge, RIPE (and the NCC) have no policy in this  
area.

While I agree wholeheartedly that every IP address should have a  
corresponding PTR entry, there are a few scenarios where this may not  
apply. For example the address space could be used on an Intranet and  
isn't visible or routed on the Internet. So putting PTRs in the public- 
facing DNS for that bit of in-addr.arpa could well be pointless. In  
other cases, the ISP/LIR may have the space but haven't yet started  
issuing it to customers. So if the addresses aren't in use, what's the  
point of adding PTR records for them? [Does everyone put 16M PTRs into  
10.in-addr.arpa on their home net?] PTRs might be missing too while a  
network is renumbered or reconfigured.

Personally speaking, it's a Good Thing some IP addresses don't have  
reverse DNS working. This is usually a very powerful hint that inbound  
SMTP is likely to be delivering spam.

Note too that RFC1912 is rather old -- the DNS landscape has changed a  
lot since it was written -- and only an INFORMATIONAL. [BIND4 config  
file snippets? Eek!] It's not a sacred text. ISTR the IETF once  
mumbled about updating/replacing RFC1912. Though this might only have  
happened in my imagination. I'm not sure if it's wise to use this RFC  
as the foundations of a RIPE policy. However that is something for the  
WG to decide.

> I hope, I found the correct mailing list for my question.

You have.

PS: Please don't say "IP" when you mean "IP address".