NAT with Multiple Public IPs

["hareram" <hareram@xxxxxxxxxx>]

Hi all

iam trying to build more than 1000 users network

now days i see some problem with yahoo

if using one IP source NAT, yahoo blocking that IP due to some problems come 
with that IP

so how can make NAT using 255 IP
with 1000users

this should do randomly using 255 IP;s

any examples

hare