perl and network addresses

[Ben Scott]

On 3/28/06, Jason Stephenson <jason at sigio.com> wrote:
> Of course, after looking back through the thread, I see Ben has already
> pretty much answered the above. ;)

  "Repetition is the very soul of the net." -- from alt.config

> Paul is using a network that is restricted to using a /19 netmask for
> addressing, but it is really using a /16 when configured. So, he wants
> to limit address to 10.0.32.0/19 but needs to configure broadcast and
> network addresses for 10.0.32.0/16. Why he needs to do that, I have no
> idea and wouldn't need to know. ;)

  Well... okay... but it's the *why* that makes me wonder.  :)

  I hope it's something interesting, and not just that he's trying to
say that he's been assigned the addresses in the range 10.0.32.0/19 on
the 10.0.0.0/16 network.  That would be *so* boring.  :)

> It seems to me that the answer is that your IP addresses are limited to
> the range of 10.0.32.0 to 10.0.63.255 with 10.0.0.0 being the network
> address and 10.255.255.255 being the broadcast address, no?

  Well, /16 means the first two octets are the network portion and the
last two octets are the host portion.  So the broadcast address (with
CIDR)  would be 10.0.255.255.  Of course, 10.0.32.0/16 would normally
be written 10.0.0.0/16, because, again, the third octet is part of the
host portion.  The host portion is really irrelevant when talking
about network numbers.  Convention says we fill the host portion with
zeros.

-- Ben