LOGANATHAN GOPINATH-XNT436 gopinathloganathan at
Thu Feb 26 14:25:22 UTC 2009

Hi all

                   Thanks for your reply ,

I tried a couple of tests , Firstly adding ping-check false into my
dhcpd.conf and mounted the dhcp on /dev/ramdisk .I measured the
performance of the server using dhcperf. To my surprise the number of
leases i.e High water mark went to a whopping number of 8090 and i was
able to get around 2300 five handshakes successfully. The subnet which i
used was so dhcp wrote a lease of 251 numbers

        When i increased the host numbers to
roughy 65000 hosts the numbers came down drastically to 92 transactions
per second from 8090. dhcpd wrote a lease file of ~3500 leases. I wonder
what could cause such a huge drop in numbers . Has anyone tried this or
faced a similar problem.






Date: Wed, 25 Feb 2009 23:41:24 +1100 (EST)

From: Glenn Satchell <Glenn.Satchell at>

Subject: Re: Ping-checkoff

To: dhcp-users at

Message-ID: <200902251241.n1PCfOvc013767 at>

Content-Type: TEXT/plain; charset=us-ascii


>Date: Wed, 25 Feb 2009 11:39:43 +0100

>From: Christof Chen <christof at>

>To: Users of ISC DHCP <dhcp-users at>

>Subject: Re: Ping-checkoff

>X-Enigmail-Version: 0.95.7

>X-Df-Sender: 285754

>X-BeenThere: dhcp-users at


>> Hi can some one help me disabling ping-check off and moving the dhcp 

>> leases write ram disk .Your help would be highly appreciated


>What about writing


> ping-check false;


>into your dhcpd.conf file?


>The location of the lease file can be changed either on compile time or

>(probably more convenient) as option -lf to the dhcpd command.


or even more convenient use dhcpd.conf entry

The lease-file-name statement

lease-file-name name;

Name should be the name of the DHCP server's lease file.

By default, this is /var/dhcp/dhcpd.leases. This state-

ment must appear in the outer scope of the configuration

file - if it appears in some other scope, it will have no


lease-file "/path/to/ramdisk/dhcpd.leases";




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the dhcp-users mailing list