Janet, it does not make sense to me.Looks like your provider is giving you several public I.P. adresses. At least on the U.S. is normal to be given a list of up to 12 or 20 I.P. when you install a internet broadband connection. Something like a half of a T1.
I will ty with a laptop or P.C. and give them each one of those adresses. if they all work, they are just public I.P.’s.
For the D300o, all what you need is one working I.P. ( you wil get it by trial with the P.C or laptop, the mask (255.255.255.248) and the default gateway. That normally is a number that start with the same digits that your address on the first three fields,and diferent on the fourth group.
Have you tried calling your provider and asking wich one of those numbers is your default gateway?????