RE: what's the meaning of the 0.0.0.0?

["David Gillett" <gillettdavid () fhda edu>]

> as far as my networking knowledge goes.....
>
> 0.0.0.0/0 is the same 0/0 is the same as "all" or "any" in firewall
> rules...

  The "/0" means that none of the address is the network portion.  So
this matches any address on any network -- it doesn't matter what's
before the "/".
 
> broadcast address is normally a.b.c.255  (which is why u cant 
> have a node with that IP)

  Formally, a broadcast address for a subnet has all of the bits in
the host portion of the address set to "1".  If the subnet is a 
Class C or larger (8 or more host address bits), then the last octet
will be 255, but smaller subnets are often used to conserve address
space, and in those cases you can have a broadcast address where a 
few high bits of the last octet are "0".

  I used to have a workstation whose address was 172.16.0.255.  I
last track of the number of people who told me (incorrectly) that it 
was illegal....

David Gillett



---------------------------------------------------------------------------
----------------------------------------------------------------------------