IPv6 Default Allocation - What size allocation are you giving out

Sat Oct 11 15:52:25 UTC 2014

On 10/10/14, Tore Anderson <tore at fud.no> wrote:
> * Baldur Norddahl
>
>> Why do people assign addresses to point-to-point links at all? You can just
>> use a host /128 route to the loopback address of the peer. Saves you the
>> hassle of coming up with new addresses for every link.

Some people think the benefit is worth the hassle.

> Why do you need those host routes?

network management, logging, troubleshooting.. you need at least one
loopback with a global address.

> Most IPv6 IGPs work just fine without global addresses or host routes.
>
> https://tools.ietf.org/html/draft-ietf-opsec-lla-only-11

Look at the discussion of the draft - there seemed >>to me<< a clear
consensus that using only link local addressing was a Bad Idea.  I
thought the caveats section made the draft worth publishing, but this
bit was left out:

   And while the caveats hint at it, there's also an operational
   complexity burden that isn't called out - the ping and NMS/discovery
   limitations also apply to human operators troubleshooting faults and
   attempting to understand a deployed topology.  LLDP and NDP add a
   layer of indirection in identifying what devices should be adjacent to
   a given interface, and only work when there is operational state
   available and links are up (whereas GUAs on interconnected devices can
   be compared by configuration alone, telling you what's supposed to be
   there).
     Erik Muller

so the draft isn't as clear as I'd hoped regarding the caveats :(

Best Regards,
Lee