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Today's Topics:
1. Re: DHCP pair messed up, second one only running cant get
primary up. (Simon Hobson)
2. Re: DHCP pair messed up, second one only running cant get
primary up. (Rob Morin)
3. RE: DHCP pair messed up, second one only running cant get
primary up. (Rob Morin)
----------------------------------------------------------------------
Message: 1
Date: Fri, 13 Jan 2017 20:30:59 +0000
From: Simon Hobson <[email protected]>
To: Users of ISC DHCP <[email protected]>
Subject: Re: DHCP pair messed up, second one only running cant get
primary up.
Message-ID: <[email protected]>
Content-Type: text/plain; charset=iso-8859-1
Rob Morin <[email protected]> wrote:
> Also the dhcpd.leases files grow too big for the /ramdisk, so we are each 10
> mins catting /dev/null into /ramdisk/dhcpd.lease! file to save space.
I can't help with the other problems, but pray you don't have to stop the DHCP
server at any time before it's re-written the compacted leases file ! Losing
the leases file is "bad" in a big way.
I can't help with the specific problem, but I would suggest that if you
lengthen the lease time (by a considerable amount) it will dramatically reduce
the rate of growth of the leases file. With a lease length of 20 minutes,
you'll have a renewal every 10 minutes (roughly) - so that's 6 lease updates to
the leases file per hour !
For example, if you were to increase the lease time to (say) 4 hours, then your
leases file would contain one record per lease (in practical terms, every
address in your pools) plus one update for roughly 1/2 the active clients.
So your lease file size will change from total of IP ranges + 6x number of
active clients, to total of IP ranges plus 1/2 the active clients.
Is there a reason for having such short leases ? It's quite short, longer
leases bring much stability and much more leeway in dealing with DHCPO service
issues !
Also, for consideration, you can have more than 2 servers in failover - but
only 2 per pool. So it's possible to have (say) 3 servers sharing the load as
A+B, B+C, and C+A. More complexity, but more scope for server failure without
losing DHCP service - and more load sharing. Of course, you can also just split
pools across an even number of servers as A+B, C+D, etc.
------------------------------
Message: 2
Date: Fri, 13 Jan 2017 21:39:01 -0500
From: Rob Morin <[email protected]>
To: Simon Hobson <[email protected]>, Users of ISC DHCP
<[email protected]>
Subject: Re: DHCP pair messed up, second one only running cant get
primary up.
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
Sorry I had a typo in my email we cat /dev/null into dhcp. leases~ file not the
active file?
Sent from Samsung Mobile
<div>-------- Original message --------</div><div>From: Simon Hobson
<[email protected]> </div><div>Date:01-13-2017 3:30 PM (GMT-05:00)
</div><div>To: Users of ISC DHCP <[email protected]> </div><div>Subject:
Re: DHCP pair messed up, second one only running cant get primary up.
</div><div>
</div>Rob Morin <[email protected]> wrote:
> Also the dhcpd.leases files grow too big for the /ramdisk, so we are each 10
> mins catting /dev/null into /ramdisk/dhcpd.lease! file to save space.
I can't help with the other problems, but pray you don't have to stop the DHCP
server at any time before it's re-written the compacted leases file ! Losing
the leases file is "bad" in a big way.
I can't help with the specific problem, but I would suggest that if you
lengthen the lease time (by a considerable amount) it will dramatically reduce
the rate of growth of the leases file. With a lease length of 20 minutes,
you'll have a renewal every 10 minutes (roughly) - so that's 6 lease updates to
the leases file per hour !
For example, if you were to increase the lease time to (say) 4 hours, then your
leases file would contain one record per lease (in practical terms, every
address in your pools) plus one update for roughly 1/2 the active clients.
So your lease file size will change from total of IP ranges + 6x number of
active clients, to total of IP ranges plus 1/2 the active clients.
Is there a reason for having such short leases ? It's quite short, longer
leases bring much stability and much more leeway in dealing with DHCPO service
issues !
Also, for consideration, you can have more than 2 servers in failover - but
only 2 per pool. So it's possible to have (say) 3 servers sharing the load as
A+B, B+C, and C+A. More complexity, but more scope for server failure without
losing DHCP service - and more load sharing. Of course, you can also just split
pools across an even number of servers as A+B, C+D, etc.
_______________________________________________
dhcp-users mailing list
[email protected]
https://lists.isc.org/mailman/listinfo/dhcp-users
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------------------------------
Message: 3
Date: Sat, 14 Jan 2017 07:23:22 +0000
From: Rob Morin <[email protected]>
To: Users of ISC DHCP <[email protected]>
Subject: RE: DHCP pair messed up, second one only running cant get
primary up.
Message-ID:
<sn2pr01mb1983ac12484ffb8aa74e9f3dca...@sn2pr01mb1983.prod.exchangelabs.com>
Content-Type: text/plain; charset="iso-8859-1"
Our lease time is governed by our client, which is huge. That cannot be
changed. :)
Rob Morin
Gestionnaire des syst?mes | Senior System administrator
T 514 385-4448 #174 DATAVALET.COM
5275, chemin Queen-Mary, Montr?al (Qu?bec) H3W 1Y3 Canada
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-----Original Message-----
From: dhcp-users [mailto:[email protected]] On Behalf Of Simon
Hobson
Sent: Friday, January 13, 2017 3:31 PM
To: Users of ISC DHCP <[email protected]>
Subject: Re: DHCP pair messed up, second one only running cant get primary up.
Rob Morin <[email protected]> wrote:
> Also the dhcpd.leases files grow too big for the /ramdisk, so we are each 10
> mins catting /dev/null into /ramdisk/dhcpd.lease! file to save space.
I can't help with the other problems, but pray you don't have to stop the DHCP
server at any time before it's re-written the compacted leases file ! Losing
the leases file is "bad" in a big way.
I can't help with the specific problem, but I would suggest that if you
lengthen the lease time (by a considerable amount) it will dramatically reduce
the rate of growth of the leases file. With a lease length of 20 minutes,
you'll have a renewal every 10 minutes (roughly) - so that's 6 lease updates to
the leases file per hour !
For example, if you were to increase the lease time to (say) 4 hours, then your
leases file would contain one record per lease (in practical terms, every
address in your pools) plus one update for roughly 1/2 the active clients.
So your lease file size will change from total of IP ranges + 6x number of
active clients, to total of IP ranges plus 1/2 the active clients.
Is there a reason for having such short leases ? It's quite short, longer
leases bring much stability and much more leeway in dealing with DHCPO service
issues !
Also, for consideration, you can have more than 2 servers in failover - but
only 2 per pool. So it's possible to have (say) 3 servers sharing the load as
A+B, B+C, and C+A. More complexity, but more scope for server failure without
losing DHCP service - and more load sharing. Of course, you can also just split
pools across an even number of servers as A+B, C+D, etc.
_______________________________________________
dhcp-users mailing list
[email protected]
https://lists.isc.org/mailman/listinfo/dhcp-users
------------------------------
Subject: Digest Footer
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------------------------------
End of dhcp-users Digest, Vol 99, Issue 6
*****************************************
