Reverse address entries

[John Horne]

On Tue, 2013-07-02 at 12:02 -0700, Eduardo Bonsi wrote:
> On 7/2/13 9:35 AM, John Horne wrote:
> >
> > We were alerted to the problem because we got long delays (around 20
> > seconds) when accessing a site doing a reverse lookup. That service
> > then, no doubt the same as with SMTP, then proceeded but without the
> > reverse lookup answer.
> >

> >
>  I do occasionally have a very short delay between 
> the main "www.mydomain" and "mydomain" but the same delay never happened 
> with the other domains/websites I am running under the same ip address. 
> I guess I could reverse my main domain to my one and only static ip 
> address and my question would be: - Does that would affect the other 
> websites I am serving using the same ip address? Thanks everyone for 
> this wealth discussion!
> 
If you are referring to my comment above about a 20 second delay, then I
should point out that the delay was caused because the reverse zone name
servers were inaccessible - access to them is blocked by our firewall.
So the client name server would try each listed name server and have to
wait for a timeout. On average this gave a 20 second delay.

It was not caused because there were no reverse zone entries to lookup.




John.

-- 
John Horne, Plymouth University, UK
Tel: +44 (0)1752 587287    Fax: +44 (0)1752 587001