Bad routes update
Craig Metz
cmetz@inner.net
Tue, 20 Jul 1999 03:06:46 -0400
[IMO this thread should probably move to deployment, but anyway...]
In message <37941D32.989451DE@iprg.nokia.com>, you write:
>> I think that it
>> would be a Very Very Good Thing if no backbone router ever had to look at
>> beyond the first 32 bits of the address, as this would make life a Whole Lot
>> Easier for hardware that is designed for the best-performance case being 32
>> bit addresses (like, oh, say, most backbone routers).
>
> Having worked on a high-speed forwarding ASIC that can do v6, I'd say
>that it makes No Difference At All. If it did, I'd suggest that the
>design would be very poor.
Vendors seem to be taking one of two approaches. One of them is to build an
extremely flexible router that will just not have a serious problem dealing
with stuff like IPv6 should it need to be dealt with. Another is to build an
IPv4 router, and anything not IPv4 might be shoehorned later but it isn't going
to be graceful.
If prefixes are restricted to /32, there just isn't a problem for either
sort of box. (On the latter sort of box, IPv6 multicast loses in a big way
though)
I agree that the 32-bit-centric (or 64-bit-centric for multicast purposes)
design is a poor one, but it exists. Okay, so maybe it's a feature and not a
bug if those boxes have a hard time....
-Craig