changing the dhcp lease time

[pickle <pickle_(_at_)_sdf_(_dot_)_lonestar_(_dot_)_org>]

Hello,

I have had VZ ADSL service for almost 4 years now.  Up till
3 weeks ago my dynamic IP has only changed a total of 4 maybe
5 times.  during the last 2 weeks it has changed 4 - 5 times
a day.  Is there something i can change to make the time last
longer or try to keep the same IP?  I have read the manpage
for dhclient.conf and im not a 100% sure how and what to add
to increase the lease time if possible.  i am currently using
a dns service running ddclient, but its not updating properly.
So if possible I'd like to keep a IP as long as possible.

THanks for any suggestions!
Dave
pickle_(_at_)_sdf_(_dot_)_lonestar_(_dot_)_org