Performance... no more than 150 leases per second?

Christian Hammers chammers at
Mon May 31 13:24:31 UTC 2010


I'm playing around with ISC dhcpd to get enough performance for a really big
network with 60000 clients that have a very short lease time of only half an
hour which calculates to about 33 leases per second.

After starting dhcpd on a pretty decent server with lots of RAM and some
3GHz cores I ended up with about 100-150 leases per second.

While this was more than I need I still wonder what exactly limits the
server. dhcpd was running with 99% CPU and almost no I/O as I put the
leases directory on /dev/shm/ (just for testing!).

That server can handle 1000 MySQL queries per second and not more than
150 dhcpd leases (at 99% CPU!) which should be a lot easy to calculate?



client:/usr/local/nom/bin/dhcperf --retain-leases  --server x.x.x.x 
  --test-duration 600 --test-load 300 --clients 100000 
  --progress --discover     

server:/usr/local/src/dhcp-4.1.1# server/dhcpd -V
Internet Systems Consortium DHCP Server 4.1.1

server:/usr/local/src/dhcp-4.1.1# grep -v ^# /etc/dhcpd.conf
default-lease-time 3600;
max-lease-time 3600;
ddns-update-style none;

deny duplicates;
one-lease-per-client true;

log-facility local6;

ping-check false;

key defomapi {
   algorithm hmac-md5;
   secret se32and6tK6xxxxxxxxx;

option domain-name-servers;

omapi-key defomapi;
omapi-port 7911;

shared-network test {
subnet netmask {
   pool {
      deny dynamic bootp clients;
   option bootfile-name "";
   option routers;

subnet netmask {

subnet netmask {

subnet netmask {

NETCOLOGNE Gesellschaft für Telekommunikation mbH
Am Coloneum 9 | 50829 Köln
Tel: 0221 2222-8711 | Fax: 0221 2222-78711

Werner Hanf
Karl-Heinz Zankel
HRG 25580, AG Köln

More information about the dhcp-users mailing list