On Fri, 23 Sep 2005, Matus UHLAR - fantomas wrote:
Good question which TTL it uses in such case. From what it looks inthe
source it ignores the TTL of the CNAME record and uses the TTL of the A
record. Obviously it should use the least of the two... Please file a bug
report on this.
I don't think so. Is should use TTL as received, but reasonable maximum and
minimum values can be used.
The key question here is what is "TTL as received" in
www.example.com ttl=60 IN CNAME server1.example.com
server1.example.com ttl=360000 IN A 172.16.4.54
when the DNS query is www.example.com A.
Squids DNS cache is quite simplistic and does not cache the CNAME
relations, only the A responses of the lookup. As a result today Squid
uses the ttl of the A record which is not entirely correct as this ttl is
for server1.example.com not the queried www.example.com. To conform with
normal DNS caching it should use the least of the two I think.
But I won't touch this without a bug report where to keep a diary of the
change and preleminary patches.
Regards
Henrik
