problem with secure subnets attribute?

[Barry Margolin <barmar@Think.COM>]

    Date: Thu, 13 Aug 1992 14:38 EDT
    From: William D. Gooch <gooch@tijeras.sw-sw.com>

    I suspect this may have to do with subnet numbers (the "c" part of your
    internet addresses) not matching properly with chaos addresses.  See the
    section "Mapping an Internet Address into a Chaos Address" in the Symbolics
    documentation.  It explains how the high-order bits of the chaos address
    are mapped into the third field ("c" in your description) of the internet
    address.  Good luck.

That section is just a suggestion for a useful convention to follow.  No
software expects or assumes any relationship between Chaos and Internet
addresses.  As it says in the first paragraph of "Choosing a Network
Addressing Scheme" (one of the sections that includes the referenced
section): "It is not necessary or required that you follow the suggestions
in this section."

For instance, in our network, we have the same low-order byte in our
Chaos and Internet addresses, but the high order Chaos address byte is
completely unrelated to Internet addresses (in particular, last year we
renumbered the Internet subnet containing all the Lispms, but didn't
change Chaos addresses).  We don't subnet our Chaosnet (we use multiport
repeaters and thin ethernet), so there's little concern about the
Chaosnet address subnet portion.  If we were, though, I would agree
with the recommendation to relate the subnet fields of both address
types (in fact, we use a scheme very much like what Symbolics recommends
for our Appletalk addresses).

                                                barmar