critical FYI secondary in partner-down

[perl-list]

The mclt as set on the primary affects the lease length available to the secondary when the primary fails. 
----- Original Message -----

> From: "Randall C Grimshaw" <rgrimsha at syr.edu>
> To: "Users of ISC DHCP" <dhcp-users at lists.isc.org>
> Sent: Tuesday, August 7, 2012 3:10:12 PM
> Subject: RE: critical FYI secondary in partner-down

> Since this is the secondary, mclt should not be set... but I did test
> this as the documentation standard 3600 as a test with no change.

> Randall Grimshaw rgrimsha at syr.edu

> From: dhcp-users-bounces+rgrimsha=syr.edu at lists.isc.org
> [dhcp-users-bounces+rgrimsha=syr.edu at lists.isc.org] on behalf of
> perl-list [perl-list at network1.net]
> Sent: Tuesday, August 07, 2012 2:29 PM
> To: Users of ISC DHCP
> Subject: Re: critical FYI secondary in partner-down

> what is your mclt set to?

> failover peer "dhcp" {
> primary;
> address x.x.x.x ;
> port N ;
> peer address x.x.x.x ;
> peer port N ;
> mclt 990;
> split 128;
> max-response-delay 60;
> max-unacked-updates 10;
> load balance max seconds 5;
> }

> mclt is only set on the primary and determines the length of leases
> when in failover on the non-primary ... from the man page:

> The mclt statement

> mclt seconds;

> The mclt statement defines the Maximum Client Lead Time. It must be
> specified on the primary, and may not be specified on the secondary.
> This is the length of time for which a lease may be renewed by
> either failover peer without contacting the
> other. The longer you set this, the longer it will take for the
> running server to recover IP addresses after moving into
> PARTNER-DOWN state. The shorter you set it, the more load your
> servers will experience when they are not communicating. A
> value of something like 3600 is probably reasonable, but again bear
> in mind that we have no real operational experience with this.
> > From: "Randall C Grimshaw" <rgrimsha at syr.edu>
> 
> > To: dhcp-users at lists.isc.org
> 
> > Sent: Tuesday, August 7, 2012 2:21:48 PM
> 
> > Subject: critical FYI secondary in partner-down
> 

> > Internet Systems Consortium DHCP Server 4.1.1-P1 as distributed by
> > Red Hat Enterprise Linux Server release 6.3 (Santiago) and possibly
> > other versions.
> 

> > To my great surprise when I brought up my secondary in partner-down
> > mode, all of the leases issued had a zero duration. This was quite
> > disruptive - All of my windows machines with dynamic leases failed.
> 

> > The work-around is to change the server to primary. (but it took a
> > bit of work and dented reputation to determine this)
> 

> > FYI FYI FYI
> 

> > has anyone else seen this?
> 

> > Randall Grimshaw rgrimsha at syr.edu
> 
> > _______________________________________________
> 
> > dhcp-users mailing list
> 
> > dhcp-users at lists.isc.org
> 
> > https://lists.isc.org/mailman/listinfo/dhcp-users
> 

> _______________________________________________
> dhcp-users mailing list
> dhcp-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/dhcp-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/dhcp-users/attachments/20120807/7e731c1a/attachment.html>