ttl for ns

Fri Aug 13 07:10:20 UTC 2004

On Thu, 12 Aug 2004, William Allen Simpson wrote:

> I remain unenlightened.  Should it be 2 days?  Or 1 hour?  And why the 
> inconsistent results?  Obsolete root glue records?

I think your first answer is from the .com gtlds which use a 2 day ttl, the 
second is from vix.com's nameservers which uses 1 hour ttl for all records.

I dont know about best practice but I dont see any reason why your ns records 
should be any different from the rest of your zone for which use a value which 
suits you and your need to make changes (if these are your network a/ptrs 
something at least 24 hours would be fine).

Having the NS records with explicitly smaller ttl wouldnt as i see it help as 
any change in nameservers as made with the registry would take the time of the 
registry plus the gtlds to become effective

Steve

> 
> A simple dig yields:
> 
> ;; ANSWER SECTION:
> vix.com.                2D IN NS        ns-ext.vix.com.
> vix.com.                2D IN NS        ns1.gnac.com.
> 
> ;; AUTHORITY SECTION:
> vix.com.                2D IN NS        ns1.gnac.com.
> vix.com.                2D IN NS        ns-ext.vix.com.
> 
> 
> But a dig directly to the ns1.gnac.com or ns-ext.vix.com server yields:
> 
> ;; ANSWER SECTION:
> vix.com.                1H IN NS        ns.lah1.vix.com.
> vix.com.                1H IN NS        ns.sql1.vix.com.
> vix.com.                1H IN NS        ns-ext.isc.org.
> vix.com.                1H IN MX        10 sa.vix.com.
> vix.com.                1H IN MX        20 fh.vix.com.
> vix.com.                1H IN TXT       "$Id: vix.com,v 1.190 2004/08/12 19:06:05 vixie Exp $"
> vix.com.                1H IN A         204.152.188.231
> vix.com.                1H IN SOA       ns.lah1.vix.com. hostmaster.vix.com. (
>                                         2004081201      ; serial
>                                         1H              ; refresh
>                                         30M             ; retry
>                                         1W              ; expiry
>                                         1H )            ; minimum
> 
> 
> ;; AUTHORITY SECTION:
> vix.com.                1H IN NS        ns.lah1.vix.com.
> vix.com.                1H IN NS        ns.sql1.vix.com.
> vix.com.                1H IN NS        ns-ext.isc.org.
> 
> ;; ADDITIONAL SECTION:
> ns.lah1.vix.com.        1H IN A         204.152.188.234
> ns.lah1.vix.com.        1H IN AAAA      2001:4f8:2::9
> ns.sql1.vix.com.        1H IN A         204.152.184.135
> ns.sql1.vix.com.        1H IN AAAA      2001:4f8:3::9
> ns-ext.isc.org.         1H IN AAAA      2001:4f8:0:2::13
> ns-ext.isc.org.         1H IN A         204.152.184.64
> sa.vix.com.             1H IN A         204.152.187.1
> sa.vix.com.             1H IN AAAA      2001:4f8:3:bb::1
> 
> 