TTL on glue records and PTR records

[chubirka]

Sorry, but I'm unclear with your response. Are you saying that the TTL for
the parent zone, gwu.edu will affect any/all records in the delegated
subdomain, va.gwu.edu, even though a different TTL has been set for any/all
records in the subdomain? What's the point then? Also, If what you say is
true and my TTL overrides the TTL for any records in the subdomain, why am I
getting such odd numbers for the TTL if the default for my zone is 2 hours?
Why do I get the following output with dig on a query of www.va.gwu.edu from
different nameservers running different versions of BIND for the parent
zone, gwu.edu?

./dig www.va.gwu.edu q-any

; <<>> DiG 9.1.3 <<>> www.va.gwu.edu q-any
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7904
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;www.va.gwu.edu.                        IN      A

;; ANSWER SECTION:
www.va.gwu.edu.         86376   IN      A       128.164.24.5

;; AUTHORITY SECTION:
va.gwu.edu.             259176  IN      NS      b.ns.va.gwu.edu.
va.gwu.edu.             259176  IN      NS      a.ns.va.gwu.edu.

;; ADDITIONAL SECTION:
a.ns.va.gwu.edu.        259176  IN      A       128.164.24.4
b.ns.va.gwu.edu.        259176  IN      A       128.164.26.1

----------------------------------------------------------------------
# ./dig @ns.gwu.edu q-any www.va.gwu.edu

; <<>> DiG 9.1.3 <<>> @ns.gwu.edu q-any www.va.gwu.edu
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 55907
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;q-any.                         IN      A

;; AUTHORITY SECTION:
.                       86400   IN      SOA     A.ROOT-SERVERS.NET.
hostmaster.n
siregistry.NET. 2001082600 1800 900 604800 86400

;; Query time: 95 msec
;; SERVER: 128.164.141.11#53(ns.gwu.edu)
;; WHEN: Sun Aug 26 11:43:18 2001
;; MSG SIZE  rcvd: 99

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24661
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;www.va.gwu.edu.                        IN      A

;; ANSWER SECTION:
www.va.gwu.edu.         86400   IN      A       128.164.24.5

;; AUTHORITY SECTION:
va.gwu.edu.             259200  IN      NS      a.ns.va.gwu.edu.
va.gwu.edu.             259200  IN      NS      b.ns.va.gwu.edu.

;; ADDITIONAL SECTION:
a.ns.va.gwu.edu.        259200  IN      A       128.164.24.4
b.ns.va.gwu.edu.        259200  IN      A       128.164.26.1

;; Query time: 12 msec
;; SERVER: 128.164.141.11#53(ns.gwu.edu)
;; WHEN: Sun Aug 26 11:43:18 2001
;; MSG SIZE  rcvd: 125


----- Original Message -----
From: "Len Conrad" <LConrad at Go2France.com>
To: <bind-users at isc.org>
Sent: Saturday, August 25, 2001 1:58 PM
Subject: Re: TTL on glue records and PTR records




>I'm a parent zone, gwu.edu, and I've been having a discussion with one of
the
>admins of my delegated subdomains, va.gwu.edu, regarding a couple of
issues:
>1. I thought that my zone TTL only affected the glue records of the
delegated
>subdomain, NOT the entire zone.

TTL´s are valid only for the zone they occur in.

>  Doesn't the SOA information in the zone file
>of the delegated subdomain set the TTL for all records in the subdomain?

no.  And recently the SOA TTL is no longer the zone default TTL nor the
negative-TTL but just the SOA´s TTL.

>2. He has multiple "A" record names pointing to the same IP addresses for
his
>nameservers

As "documentation" records, those NS records in his zone file won´t be
queried by DNS´s following referrals.  So the delegation NS records (in
your DNS as parent) will provide the effective TTL´s.

Len


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