DHCP failover and "secs" value

Simon Hobson dhcp1 at thehobsons.co.uk
Tue Oct 23 08:24:27 UTC 2012

Abu Abdulla alhanbali wrote:

>- In many cases, one server will end up with more active leases than
>the other one, balancing is done in a configurable way. How the lease
>ownership is shifting from one server to the other one since the user
>will continue to request from the same server he got the IP from.

AFAIK the servers do not balance active leases, only free leases. By 
default they will balance the free leases so that each server has 
about half of them. This does mean that the active leases may not be 
balanced, and in particular, if you have a prolonged outage on one 
server then you may end up with the active leases very unbalanced.

However, unless the servers are "underpowered" for the load, then 
this should not matter. In the event of failuser, the remaining 
server can still take over the whole range. In normal operations, 
each server will continue to renew the leases it holds.

Over time, as clients come and go, the active leases will tend to 
balance as new ones will get balanced between the servers.

Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.

More information about the dhcp-users mailing list