[dlc at halibut.com: Re: Tracking all RRsets for a given host]

David Carmean dlc-bu at halibut.com
Tue Jun 19 19:42:20 UTC 2001


On Fri, Jun 15, 2001 at 03:35:03AM +0200, Brad Knowles wrote:

> 	Unfortunately, multiple PTR records just don't work the way most 
> people expect them to.  Virtually all applications I know of expect 
> there to only be one canonical name for a host, and they only 
> allocate one slot in their data structures to hold that information.
> 
> 	Now, that said, since you're writing your own application, you 
> could use a linked list (or a doubly-linked list, or a b-tree, or 
> some other structure that would allow an indefinite number of 
> entries) for the PTR records, and that would probably be okay.  It's 
> certainly not illegal from the DNS point of view, it's more an 
> application problem.


It's only a tool to mange DNS, applying our rules for reserving 
addresses, etc.  All the traditional (broken?) apps remain in use.


> >              And I guess multiple CNAME records are out of the
> >  question....
> 
> 	Multiple CNAME records for what?

As in:

    somehost-le0        IN      A       192.168.1.1
    somehost-qfe0       IN      A       192.168.2.2
    somehost-qfe1       IN      A       192.168.3.3
    somehost            IN      CNAME	somehost-le0
                        IN      CNAME   somehost-qfe0
                        IN      CNAME	somehost-qfe1


> 
> 	If you want to get all this stuff into a single RRset, so that 
> you can make sure you get atomic inserts and deletions (although you 
> don't get locking or two-phase commit), I think you're going to have 
> problems if you create unique host names for each interface of 
> multi-homed hosts.  You'll only get stuff tied together into a single 
> RRset if it has exactly the same label, class, and record type.
> 

It sounds like I won't be able to do that, strictly.  Thanks.




More information about the bind-users mailing list