smurf's attack...

Michael K. Sanders msanders at
Fri Sep 5 21:56:33 UTC 1997

In message <F8F9425FD8 at>, DAVE NORDLUND writes:
>> Likewise, not all broadcast adresses necessarily end with .255, 
>> so filtering .255 won't help anyway in the presence of something
>> like a /25 with a X.X.X.127 broadcast.
>Agreed but it is not easy for a hacker to determine CIDR masks.  It

I'm sorry, but that's naive.  Unless you've taken steps to prevent
it, or you're just lucky, it's trivial to find out a lot of
things. Your mail server, for example, has a mask of 0xFFFFFF00. 

Another network at apparently has a mask of 0xFFFFFC00, 
and another is 0xFFFFF800.

:: Mike ::

More information about the NANOG mailing list