nanog mailing list archives
Re: IPv6: numbering of point-to-point-links
From: Marco Hogewoning <mch-nanog () xs4all nl>
Date: Mon, 24 Jan 2011 14:10:48 +0100
While reading up on IPv6, I've seen numerous places that subnets are now all /64. I have even read that subnets defined as /127 are considered harmful.
RFC3627, with a lot of discussion in the IETF on this. See also https://datatracker.ietf.org/doc/draft-ietf-6man-prefixlen-p2p/
However while implementing IPv6 in our network, I've encountered several of our peering partners using /127 or /126 for point-to-point links.
I personally don't any benefit in using /126 subnets.
What is the Best Current Practice for this - if there is any? Would you recommend me to use /64, /126 or /127? What are the pros and cons?
From an operational point of view there is a risk that be using /64 somebody can eat away a lot of memory by either scanning or even changing addresses. This is also described in the draft above... I would personally recommend to at least always assign the /64, even if you would decide to configure the /127. RFC 3627 has been around long enough that you will keep running into equipment or software that won't like the /127. In which case you can always revert back to /64. This will also allow you to use easy to remember addresses like ::1 and ::2, saving you the headache of a lot of binary counting. Grtx, Marco
Current thread:
- IPv6: numbering of point-to-point-links Lasse Jarlskov (Jan 24)
- Re: IPv6: numbering of point-to-point-links Carlos Friacas (Jan 24)
- Re: IPv6: numbering of point-to-point-links Grzegorz Janoszka (Jan 24)
- Re: IPv6: numbering of point-to-point-links Marco Hogewoning (Jan 24)
- Re: IPv6: numbering of point-to-point-links bmanning (Jan 24)
- Re: IPv6: numbering of point-to-point-links Jack Bates (Jan 24)
- Re: IPv6: numbering of point-to-point-links Crist Clark (Jan 24)
- Re: IPv6: numbering of point-to-point-links Owen DeLong (Jan 24)
- Re: IPv6: numbering of point-to-point-links Randy Bush (Jan 24)
- Re: IPv6: numbering of point-to-point-links Blake Hudson (Jan 31)
- Re: IPv6: numbering of point-to-point-links Randy Bush (Jan 31)
- Re: IPv6: numbering of point-to-point-links Blake Hudson (Jan 31)
- Re: IPv6: numbering of point-to-point-links Randy Bush (Jan 31)
- Re: IPv6: numbering of point-to-point-links bmanning (Jan 24)
- Re: IPv6: numbering of point-to-point-links Gary Buhrmaster (Jan 31)
- Re: IPv6: numbering of point-to-point-links Carlos Friacas (Jan 24)