[ntp:questions] Is it possible to run NTP daemon on loopback interface ?

Koos van den Hout koos at cs.uu.nl
Wed Dec 22 10:27:14 UTC 2004

David Woolley <david at djwhome.demon.co.uk> wrote:
> In article <mailman.95.1103620101.54146.questions at lists.ntp.isc.org>,
> Aravind babu <aravindforn at yahoo.co.in> wrote:

>>           My requirement is to run ntpd on loopback interface.How to
> **           achieve that.I checked the code and i tried by adding some
> **           bind calls in code.But i am unable to run ntpd on loopback.

> Could you please find someone that you can talk to locally, who
> has a strong understanding of how IP works, and discuss
> exactly what you are trying to do in IP routing terms.   My expectation
> is that they will confirm that what you are trying to do to solve
> your problem is fundamentally impossible unless the server is the same
> machine as the client.

I think there is a little misunderstandig here. What is 'loopback' on for
example cisco routers is a 'virtual interface' that you can give any IP
address, so you can select the 'right' interface to be the source of
traffic, instead of the interface choice depending on routing.

What is loopback on Unix is, and traffic for that IP can indeed
not leave the system.

What the original poster wants is 'use *this* source address for ntp
requests, independent of routing'.


Koos van den Hout, herding Suns and networks as koos at cs.uu.nl
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