Re: Caching SERVFAIL?

dnscache before djbdns-1.05 used to cache SRVFAIL responses (with
support for actually caching them as SRVFAIL, rather than turning them
into NXDOMAIN).  Dan specifically removed this from djbdns-1.04, with
a CHANGES comment "dnscache no longer caches SERVFAIL. per-ip is
obviously the way to go."

I recommend against this patch.

On Tue, Mar 24, 2009 at 4:11 PM, Mark Johnson <[email protected]> wrote:
> I got this patch (djbdns-dnscache-NCACHE.patch ) via Jason Haar:
>
> Author: [email protected]
> diff -pr djbdns-1.05.orig/query.c djbdns-1.05/query.c
> *** djbdns-1.05.orig/query.c    Fri Mar 10 15:07:10 2006
> --- djbdns-1.05/query.c Fri Mar 10 15:08:27 2006
> *************** static int doit(struct query *z,int stat
> *** 211,216 ****
> --- 211,217 ----
>    if (state == 1) goto HAVEPACKET;
>    if (state == -1) {
>      log_servfail(z->name[z->level]);
> +     cachegeneric(DNS_T_ANY,z->name[z->level],"",0, 200); // For 200 seconds
>      goto SERVFAIL;
>    }
>
> I think this is the problem Dinesh was trying to solve:
>
> http://marc.info/?l=djbdns&m=113760199401605&w=2
>
> Jason's problem:
>
> http://marc.info/?l=djbdns&m=114192951031335&w=2
>
> I started looking at RFC 2038 (NCACHE), but my eyes glazed over pretty
> quick.  It seems to me, however, that this patch is addresses only
> section 7.1 - Server Failure (Optional).  Comments?
>