Subnetting Practices

[Michael W. Oliver]

On 2007-07-14T11:16:56-0700, Seth Mattinen wrote:
> Roland Dobbins wrote:
>> On Jul 14, 2007, at 10:44 AM, Seth Mattinen wrote:
>>> This seems kind of wasteful to me, so if anyone out there can clarify why, I'd appreciate it.
>> Not only is it wasteful, but it's a security risk, as it essentially turns one's router into a sinkhole 
>> for any type of scanning activity or DDoS crafted to exploit this inexplicable practice, IMHO.
> 
> I'm inclined to use something *way* smaller (like a /126 since /127's are bad) for router links. I thought 
> the push behind IPv6 was because we're running out of v4 space, and I see standard practice blowing a /64 
> on a link that'll never have more than 2 devices on it. Lots of stuff I read encourages seemingly wasteful 
> practices in v6 space as a good thing and it confuses me.
> 
> ~Seth

Feel free to use /126 for p2p links, I surely do.  The only use for /64
for me is when using stateless auto-configuration where the router
dishes out the 64 network bits and the remaining are EUI64.  Beware of
embedded devices that will be hard-coded to expect 64 network bits, no
more and no less, just because the RFCs say so.

IMHO, the whole practice is extremely wasteful.  Yes, 128 bits is a lot,
but then again, 32 bits seemed like a lot at one point in time.  Just
because you have the space to waste doesn't mean you have to waste it.

Back into lurk mode...

-- 
Mike Oliver, KI4OFU
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