ZERO TTL ?!?

[Barry Margolin]

In article <38C7EBD3.6888FF8B at sunbeam.ch>,
Andre Schwaller  <andre at sunbeam.ch> wrote:
>But if you do nslookup (set sebug) from the internet i get TTL set to
>Zero.
>
>ns1    86400 IN NS    195.162.167.201
>ns1    86400 IN NS    10.0.3.1
>ns2    86400 IN NS    195.162.167.202
>ns2    86400 IN NS    10.0.3.2

Those TTLs are 86400, not 0, so what are you talking about?  Does this only
happen when you try to look something up in your domain?

Is this what you're talking about?  My guess is that your NAT router is
doing this.  I think it sets the TTL of translated records to 0 for the
benefit of dynamic translations that might be deleted soon.  What it
probably *should* do is use the idle timer of the translation as the TTL,
and static translations should probably not have the TTL modified at all.
Complain to the NAT vendor.

% dig autobox.ch any !$ +norecurse
dig autobox.ch any @195.162.167.202 +norecurse

; <<>> DiG 2.2 <<>> autobox.ch any @195.162.167.202 +norecurse 
; (1 server found)
;; res options: init defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10
;; flags: qr aa ra; Ques: 1, Ans: 6, Auth: 2, Addit: 4
;; QUESTIONS:
;;	autobox.ch, type = ANY, class = IN

;; ANSWERS:
autobox.ch.	86400	MX	10 mail.autobox.ch.
autobox.ch.	86400	MX	5 mail.autobox.ch.
autobox.ch.	86400	A	194.209.219.94
autobox.ch.	0	NS	ns2.autobox.ch.
autobox.ch.	86400	NS	ns1.autobox.ch.
autobox.ch.	86400	SOA	ns1.autobox.ch. hostmaster.autobox.ch. (
			2000030942	; serial
			10800	; refresh (3 hours)
			3600	; retry (1 hour)
			604800	; expire (7 days)
			86400 )	; minimum (1 day)

;; AUTHORITY RECORDS:
autobox.ch.	0	NS	ns2.autobox.ch.
autobox.ch.	86400	NS	ns1.autobox.ch.

;; ADDITIONAL RECORDS:
mail.autobox.ch.	86400	A	194.209.219.94
ns2.autobox.ch.	0	A	195.162.167.202
ns2.autobox.ch.	86400	A	195.162.167.202
ns1.autobox.ch.	86400	A	195.162.167.201

;; Total query time: 187 msec
;; FROM: tools to SERVER: 195.162.167.202
;; WHEN: Thu Mar  9 15:50:46 2000
;; MSG SIZE  sent: 28  rcvd: 256

>---------------------
>but if i delete the internal ip's it does work but then everything is
>going to wend on my provider which is not wat i want (traffic for
>nothing! and in switzerland traffic is extreamly expensive)

I'm not sure what you mean here.  If your users are pointing to your DNS
server, they'll never go out to the ISP's nameservers when they're looking
up names that your server hosts.  NS records are only used by remote
servers to find your servers.

-- 
Barry Margolin, barmar at bbnplanet.com
GTE Internetworking, Powered by BBN, Burlington, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
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