copying the question section

Paul Vixie paul at
Sun Aug 4 02:24:01 UTC 2002

> In the positive response case, the name in the question section will
> almost always cause a later name to be compressed, I'd estimate that in
> the average case, omitting the question would save 6 bytes.  (a compressed
> name, type, and class).  In the referral or nxdomain response, there won't
> be a later name matching the qname exactly, but I still wouldn't expect a
> savings of more than 20 bytes or so.

statistically speaking, the root servers only send back referrals and
nxdomains.  the savings is the size of the maximum average qname, which
is about 80 octets.

> Are there that many messages that are in the 513-550 byte range that 
> this would make a difference?

that's not the issue at all.  it's the wish to add more root glue, like AAAA
RR's for the existing servers, and the inability to do so because the qname
is taking up all that room.

don't worry, we'll figure something else out.

More information about the bind-workers mailing list