22 Feb
2012
22 Feb
'12
9:54 p.m.
On Wed, 22 Feb 2012 15:19:31 -0800, David Josephson WA6NMF <wa6nmf(a)josephson.com>
wrote:
I am puzzled that we want to assign 44-net addresses
one by one as shown
in amprhosts rather than as subnets. Perhaps there is a historical
reason for that. The routing table could get to be very large (we can hope!)
Subnetting is reasonable to do but we still have to assign addresses in
those subnets one at a time in order to get DNS entries for them and to
enable them in the Internet ingress filter.
The division of the AMPRNet space into the existing blocks of addresses
was primarily for administrative convenience, not as a mandated subnetting
scheme.
Subnets should probably track routers/gateways; that is, each
router/gateway should have a small subnet associated with it. That would
help to keep the routing table at a reasonable size. Since routers often
serve a specific geographical area, having regional subnets could be a fairly
good way to assign addresses.
The hard question is what size region and what size subnet?
The implication is that there will be a router for each region, which is
what we've been doing in many places anyway. Perhaps major cities is a
reasonable way to divide an area into subnets. But there are also flat
networks which need only one router even though they span multiple cities.
Ideas?
- Brian