Hi Usman,
Usman Latif said the following on 21/09/12 13:46 :
And this point is: "What is the IETF / IANA / APNIC best-practice /
recommendation for assigning IPv6 addressing to strictly point-to-point
links where we know there will never be more than one device on each end
of the link for the foreseeable future"
I have gone through some RFCs (RFC 4291, RFC 5375, RFC 3627, RFC 3177 /
6177 and RFC 6164)
RFC 6164 should give you the guidance you need.
As a network engineer with IPv4 and some IPv6 background, I am inclined
to use /126 addressing on strictly point to point links - but after
discussion with peers in the industry have learnt that the
recommendations are to use /64
I want to know rationale behind using a /64 on strictly point-to-point
links where we know there will never be more than one device on each end
of the link?
Perhaps ask your peers who recommended addressing a point to point link
as a /64?
To me using something like a /126 saves and eases the management /
support of the p2p links and gives it more predictability and control.
It certainly mirrors the /30 for point to point links in IPv4.
I guess what I am looking for is some guidelines on why using subnet
length greater than /64 is discouraged and whether there is likelihood
that any future implementation (of protocol stacks) of IPv6 could create
problems for deployments where engineers/architects have chosen to
implement /126 on strictly p2p links
The general guidelines I see most folks following now are to number a
point-to-point link as a /127, but reserve the entire /64. You then
avoid the ping-pong problem described in RFC6164, but avoid the
possibility of being caught out by future developments by numbering all
your point-to-point link sequentially as /127s (I've been there for IPv4
years ago - not pleasant).
Saying all the above, most operators I've seen are using /64s, /126s or
/127s for point to point links (reserving the entire /64 for the link).
The use of /127s is the most recent development, and is certainly what
I've been doing in my IPv6 workshop labs in the last couple of years.
Hope this helps!
philip
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