who is using multiple failover pairs on the same server

[Gordon A. Lang]

I have it working, and it works just fine so far, but I haven't put it under 
load yet.

But my concern is whether or not this sort of configuration might challenge 
the code in a way that hasn't been tested and/or in a way that will affect 
performance/capacity of the servers.

The reason for my concern is because a person working for an IPAM software 
vendor has asserted that ISC DHCP should not be trusted to do any failover 
relationships other than single pairing based on their testing.

Is there any possible validity to his claim?

Is the code that mates leases to the correct failover peer tricky or 
something?

--
Gordon A. Lang


----- Original Message ----- 
From: "Glenn Satchell" <Glenn.Satchell at uniq.com.au>
To: <dhcp-users at isc.org>
Sent: Thursday, August 07, 2008 8:26 AM
Subject: Re: who is using multiple failover pairs on the same server


>
>>From: "Gordon A. Lang" <glang at goalex.com>
>>To: <dhcp-users at isc.org>
>>Subject: who is using multiple failover pairs on the same server
>>Date: Thu, 7 Aug 2008 03:06:03 -0400
>>
>>I am using 3.1.1.
>>
>>I have four servers, A, B, C, and D.
>>
>>First failover pair is A-B where A is primary.
>>Second failover pair is B-C where B is primary.
>>Third failover pair is C-D where C is primary.
>>(yes, there is a legitimate reason for wanting this)
>>
>>Has anyone experienced any issues with this sort of setup?
>>I've heard from some people that they had various difficulties
>>with anything other than simple one to one pairing.  What I'm
>>wondering is if maybe the problems he experienced was just
>>a misconfiguration, or maybe a problem fixed in version 3.1.1.
>>
>>Anyone?
>
> I set up a network once where we had a single central server, and
> several remote offices. The subnet in each remote office had the
> centralserver and the respective local server as the failover peers for
> that subnet. Seemed to work quite well. I ended up building the
> dhcpd.conf file from separate components so that the right subnet
> definitions were included for each particular server. We did this for
> redundancy - a failed link with the central site should still allow
> dhcp to continue operating.
>
> Your system should work ok. Just remember to get the failover pair
> statements to match up properly, and the right failover name in each
> pool definition. A bit of testing should confirm that yo have
> everything right.
>
> regards,
> -glenn
>
>