Wildcards in reverse DNS

Edward Lewis Ed.Lewis at neustar.biz
Mon Jan 8 13:22:37 UTC 2007

At 11:24 -0800 1/5/07, Clenna Lumina wrote:
>Edward Lewis wrote:

>>  I don't really agree with that.  Many protocols were built without
>>  unique identifiers, such as DNS, assuming they could rely on IP
>>  addresses and port numbers.
>I'm just curious, what sort of problems does DNS have behind NAT in your
>experience? I'm running Bind 9 behind a NAT that both manages a couple
>domains I own and acts as the main DNS server for my tiny network, thus
>queries going either way - seeking athorative answeres for the domains I
>own, and the other way seeking google.com, etc - without any problems.

I haven't seen any...I mentioned DNS as an example of a protocol that 
relies on lower layer identifiers (particularly in query processing).

>What I think could be a solution would be to have IPv6 became the main
>protocol, with IPv4  transparrently "existing" within it, so to speak,
>for backwards compatibility, I'd imagine no programs that rely on IPv4
>would have to be rewritten.

I can't think of any technological transition (computer network or 
otherwise) that used the new method to convey the old during 
transition, it has always been the other way around.  One of the 
failings of failed technologies is their failure to have a transition 
plan that relied on bootstrapping from old to new.  I first thought 
this in the early 90's when looking at ATM, which assumed everything 
would be cell-based and that there was no need for it to sit 
side-by-side with packet technology, instead, there would be an 
adaptation layer.

Successful transitions do feature carrying old in new, but that is 
after the new technology is well established and the old is in its 

>Say every ISP in the world just switches over to IPv6.

There's an expression that captures my reaction to that assertion - 
"First boil the ocean."  I.e., ISP's can "just switch" over to IPv6. 
ISPs are cash poor for two reasons - going into debt in the boom era 
has them reeling and data tranist is a commodity service.  There is 
no wood to light a big enough fire to boil an ocean-sized pot of 

>In fact, I'm actually suprised the designers of IPv6 didn't do this.
>(Well, if they actually did, then I apologize, though I can find no info
>on that.)

THey didn't, they did draw up IPv6 in IPv4 because that could work. 
IPv6 would be hobbled but IPv4 could carry it around.  Putting IPv4 
into IPv6 would be like putting cars into boats and trying to cross a 

Edward Lewis                                                +1-571-434-5468

Dessert - aka Service Pack 1 for lunch.

More information about the bind-users mailing list