Subnetmasks

nelson@crynwr.com
16 Apr 1996 17:12:57 GMT

Henrik Juul Hansen writes:
> Hi tkined constructors/users!

> How do I use subnetmasks in tkined? Both with ip_discover and
> tkined in general. Is there a data structure for storing this
> information?

Well, in theory, you can store it in the domain name system. What you
do is name your networks (the zero address). So for my network, that
would be crynwr-net.crynwr.com, with an address of 192.203.178.0. And
in the 178.203.192.in-addr.arpa zone, you put a PTR entry to
crynwr-net.crynwr.com. AND (here's the tricky and clever part), you
have an A record on 0.178.203.192.in-addr.arpa, which is the subnet
mask! Very sublime. Here's the lines in their entirety:

db.crynwr.com:
crynwr-net.crynwr.com. IN A 192.203.178.0

db.178.203.192:
178.203.192.in-addr.arpa. IN PTR crynwr-net.crynwr.com.
178.203.192.in-addr.arpa. IN A 255.255.255.0

There's an RFC on all this stuff, but I don't remember what it is off
the top of my head. It's one of the ones that comes with BIND.

Now, having said that, I don't know if tkined knows enough to look for
this information.

-russ <nelson@crynwr.com> http://www.crynwr.com/~nelson
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