Linux-Hams archive - January 1997: Re: Netmask, Broadcast etc

Re: Netmask, Broadcast etc

Bob Nielsen (rdxbekug@hocnet.net)
Fri, 3 Jan 1997 04:32:15 -0700 (MST)


On Fri, 3 Jan 1997, Terry Dawson wrote:

> Barry Winch wrote:
>
> > Using a standard Mask of 255.255.255.0 Gives a Broadcast of
> > 44.135.96.255, but does NOT allow me to connect to 44.135.96.xx
> > stations outside of my LAN, so I tried a mask of 255.255.255.255,
> > which now gives a broadcast of 44.135.96.125 and allows me to connect
> > to systems on the LAN (once I have added them to the route file) and
> > ANY system in the outside world.
> >
> > Is the above an acceptable approach, my main concern is that the
> > Broadcast of 44.135.96.125 will limit "visibility" to 44.135.96.126
> > and .127
>
> Barry, in my home network I had my local IP address coordinator
> (me in this case) allocate me a contiguous block of IP addresses
> thusly:
>
> 44.136.8.96 -> 44.136.8.103
>
> These address through the magic of binary are all identical except
> the last three bits. These addresses I allocated to the hosts on
> my lan. The netmask I use for the lan is 255.255.255.248 which
> captures them all neatly. I use 8.96 as the network address and
> 8.103 as the broadcast address.
>
> Everyone else can reach me using:
>
> route add 44.136.8.96/29
>
> talk to your local IP address coordinator, ask them for a
> "29 bit subnet" and you should be able to do the same thing.
>
> regards
> Terry
>
>

kf7tp, the IP address coordinator for Arizona reassigned all the addresses
last year so that everyone has a 30 bit address assignment, allowing four
IP addresses per station.

Bob

----
Bob Nielsen Internet: fpzrwcc.ijadfur@trinity-house.org.uk
Tucson, AZ AMPRnet: zayyn@trasys.be
AX.25: gqvbrcv@qmw.ac.uk
http://www.primenet.com/~nielsen