Using IPv6 with prefixes shorter than a /64 on a LAN
fernando at gont.com.ar
Wed Jan 26 22:09:43 CST 2011
On 26/01/2011 06:14 a.m., Owen DeLong wrote:
>>> That said. Any size prefix will likely work and is even permitted by
>>> the RFC. You do run the risk of encountering applications that assume
>>> a 64-bit prefix length, though. And you're often crippling the
>>> advantages of IPv6.
>> Just curious: What are the advantages you're referring to?
> 1. Sparse addressing
This comes at a cost, though.
> 2. SLAAC
> 3. RFC 4193 Privacy Addressing
Privacy Extensions "solve" (*) a privacy issue *introduced* by SLAAC
embedding the MAC addresses in the IID. -- So, if anything, I deem this
as a patch, rather than a feature.
(*) there is some bibliography about the effectiveness of privacy
addresses. Some have even argued that they are harmful.
> 4. Never have to worry about "growing" a subnet to hold new machines.
As in #1, this comes at a price.
> 5. Universal subnet size, no surprises, no operator confusion, no bitmath.
With quite a bit of experience with subnetting (from IPv4), I doubt this
can be flagged as a benefit.
e-mail: fernando at gont.com.ar || fgont at acm.org
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