renewing dhcp lease early

[Don Russell]

Is there a way to force the dhcp renewal process early?

I'm having some troubles with my ISP and want to use ethereal to capture 
the traffic during the renewal process.

I started ethereal and then did a "service network restart", but that 
caused ethereal to choke because it complained that the network stopped.

Specifically I'm trying to capture the traffic where the dhcp client 
talks to the dhcp server directly, not the broadcast traffic... the 
broadcast method all works, but I'm getting icmp 3/3 (port unreachable) 
back from the dhcp server...

Thanks for any tips.

Don