config question

how do i set squid to go to an uplink squid on ALL occasions EXCEPT when
a) something is local
b) the uplink is down - not responding
c) go to a different uplink IF the main one is down, and bind it to a specific
   interface on the NEW uplink

i have inside firewall set to none with some domains above that are local...
but id prefer to do it based on IP address of the server... if i just do
our C-Classes then i wont have to add every domain.

     ---------------------------------------------------------------------
    | Skeeve Stevens - myinternet personal.url: http://www.skeeve.net/ |
    | email://[email protected]/ work.url: http://www.myinternet.net/ |
    | phone://612.9876.4527/ mobile://0414.SKEEVE/ [753-383] |
    | No kids, no chat room, no smiley faces. |
    | - This email is (c) 1997 by Skeeve Stevens - All rights reserved - |
     ---------------------------------------------------------------------
Received on Thu Nov 27 1997 - 04:48:33 MST