Re: [Netdisco] Reverse DNS Lookups

[Ingen S. J. v. (ICTS) <j.v...@ut...>]

On Mon, 2010-11-08 at 15:22 +0000, Robert Kerr wrote:
> On Fri, 2010-11-05 at 19:52 +0000, Joel Krauska wrote:
> > Why not incorporate this in to the database?
> 
> > I have a lot of IPs which don't return reverse DNS, so when I load the 
> > device.html file with reverse dns lookups on, it can take up to 2 
> > minutes to load.
> 
> > I've disabled the lookup, but why not just run this after each arp 
> > lookup and store the reverse dns for a time?
> 
> > (doing it on every page load seems wasteful)
> 
> I'd say doing it every page load is far less wasteful that doing it
> every arpnip. Your mileage of course may vary - it depends how many IPs
> you have in netdisco, how often you run arpnip, how often you access the
> netdisco web UI, and how many ports you have per device. In my case
> doing it every arpnip would result in 30k lookups an hour.

Perhaps we could cache the DNS results that we do on page display, for a
certain amount of time? That way at least a page refresh doesn't result
in a lot of new DNS requests...

We'd also have to cache negative results though...


Regards,

Jeroen van Ingen
ICT Service Centre
University of Twente, P.O.Box 217, 7500 AE Enschede, The Netherlands