[NTLUG:Discuss] IP super/sub-netting maddness

[Richard Geoffrion]

Ok... I think I'm asking the impossible here because no matter how I 
calculate it the bits don't line up...but here goes. 

Can you supernet multiple subnetted network ranges when they don't fall 
on bit boundaries??

For instance, 

Networks 192.168.0.0 mask 255.255.255.0 and 192.168.1.0 mask 
255.255.255.0 can be referred to / supernetted  by changing the mask to 
255.255.254.0.  This gives 510 available hosts on the same network 
instead of just 254.


Now... what about a situation where I have a 125 ip address DHCP scope 
on a 192.168.1.0/24 segment...and (in my infinite wisdom and foresight) 
I started it at 60.  Yes... 60. Just pick a number...ANY number.  Throw 
a dart -- WHOO HOO!  Triple 20!   The DHCP scope is 192.168.1.60-185.

Now that the DHCP scope is set.. let's put servers and other special 
statics from 1-47 and printers from 224-254... YEAH!! Let's just trash 
both /25 subnets with 'stuff' we can't move.

Now that we have all our static hosts and printers integrated... .how 
about we firm up these ranges (which is where I got those numbers above) 
and see if there is a way to reference the DHCP scope by network.  
Hmmm... nope.. BUT.. if I modify the dhcp scope to 
be...192.168.1.64-192....then the DHCP scope will fall on the ranges of 
several subnets.

So...is it possible to supernet the subnets?  (I know it sounds 
ridiculous...and unlikely...but if it's possible it would be a great 
learning experience for me...not to mention making firewall rules 
easier. :) )

Afterthought...  In the history of TCP/IP...has a subnet mask such 
as........well...no...that'd be an invalid subnet mask.  hm... still... 
has something like (11111111.11111111.11111111.1101xxxx) 255.255.255.200 
ever been used?

-- 
Richard
Nope...I'm not smoking anything....
(not to say I'm not crazy...just not smok'n)