Getting a "portable" /19 or /20
Sean M. Doran
smd at clock.org
Wed Apr 11 02:38:12 UTC 2001
Greg Maxwell <gmaxwell at martin.fl.us> writes:
| > Aggregation buys time, that's it. Aggregation does not make the
| > current routing methods any more scalable.
| In IPv4 yes, because you can't have perfect aggregation, too much network
| multihoming and old prefixes and it's to painful to change address blocks.
| In IPv6, if implimented right aggregation provides for virtually limitless
| scalability for unicast traffic.
Perfectly aggregated networks are star-shaped.
Any more complicated topology cannot be perfectly aggregated.
In real networks, aggregation at best follows a "reasonable"
trade-off between optimizing and stabilizing route selection.
Not everyone will agree on what is a "reasonable" balance.
Result: some people unhappy about suboptimal routing ("my packets
to my neighbour across the street go through another country") and
some people unhappy about too-great dynamicism ("damn, time to upgrade
to a faster processor, more memory, faster memory, etc etc etc").
This is a result of the CIDR addressing architecture and is
INDEPENDENT OF THE NUMBER OF BITS IN AN ADDRESS.
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