retfarcratS,

If your wanting to set a default rule in the sonicwall to block all ports except ones you specify , do the following...

from the admin screen of your firewall, go to Access then rules,
Click add new rule.

Select Action = Deny
Select Service = Default
Source = *
Destination = LAN

Hit update & your done, then just add rules for the ports / services you wish to allow.

HTH