Re: [Openvpn-users] Network monitoring [was Re: Answering on the same interface where the request came from]

[Martijn L. <m...@rt...>]

Charles Duffy wrote:

>On Thu, 24 Feb 2005 23:16:54 +0100, Martijn Lievaart wrote:
>
>  
>
>>>Eh? Can't Nagios support DNS? Script up your OpenVPN instances to
>>>register both reverse and forward DNS for connecting clients.
>>>      
>>>
>>It's not an DNS issue. Nagios does not use DNS, how can it work reliably
>>if it did?
>>    
>>
>
>You want to monitor whether the host with CN foo is up, but you don't know
>which OpenVPN instance that host will be connected to. You configure your
>OpenVPN instances to register foo.vpn.company.com in DNS whenever such a
>system connects, and have Nagios query the services not of 1.2.3.4 but
>rather of foo.vpn.company.com, which the DNS server will always redirect
>to the right place. What's so inherently unreliable on unworkable about
>this? It's literally what I do (I'm using homegrown network monitoring
>software rather than Nagios).
>
>  
>

You are right, I misunderstood. Normally you don't want your nagios 
checked host to be resolved by DNS, if some local DNS breaks, it does 
not neccessaraly mean the host/service is broken. In this case however, 
using DNS is part of checking the service.

M4