/24 is the class-c of addresses... 10.0.0.0-255 /8 would be a HUGE block... basically 2^(32 - 8) - 2 ck j davis wrote: > hello, > Not to long ago my friend help me understand subnets....but i > forgot...damn! > to express this 209.155.161.1-254 could i say > 209.155.161.0/8 or would it be /24. I know i should know this..:( > > thanks, > jd >