On 15 Apr 2004 at 17:17, Bruce Richardson wrote about
"Re: [Exim] @mx_any and 127.0.0.1":
| On Thu, Apr 15, 2004 at 09:09:13AM -0700, Fred Viles wrote:
| > On 15 Apr 2004 at 16:30, Adam D. Barratt wrote about
| > "Re: [Exim] @mx_any and 127.0.0.1":
|...
| > | Indeed. Setting it to
| > |
| > | MX 0 .
| > |
| > | is more usual,
| >
| > It is? Doesn't that amount to abuse of the root servers?
|
| Not really. . will never have an A record.
The abuse is causing unnecessary queries. The lack of an A record
will not prevent the queries being made. If anything, it will
increase the number of queries because the NXDOMAIN response will not
tend to be cached as long as an A record would be.
| I don't see this bringing down the root servers.
I don't think it's necessary for the extra load you unnecessarily put
on someone else's server to "bring it down" before it can be
considered abusive.
| > I would think
| >
| > @ MX 0 name.that.has.no.a.record
| >
| > would be better practice.
|
| Which would still involve a DNS query to the root servers at some point.
No, it would cause no extra root queries. The MX target is in-zone,
so the querying server already has the delegation records.
- Fred
