[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [RAM] 6to4

I am wondering where 6to4 fits on the LISP continuum. 

Well, it can work serially. Here is the scenario I am referring to:

o An IPv6 packet is received by an ITR.
o The DA is an EID so a mapping lookup is done to yield a locator in the 2002::/16
range.
o The ITR prepends a IPv6 header.
o The platform specific code in the router will try to resolve a next- hop and find
out there is no IPv6 next-hop for the outer DA. So it resolves the address to
an IPv4 address which follows the 2002 bits. The ITR prepends an IPv4 header.
o The ITR sends the packet out the interface where the IPv4 DA is resolved to.

Correct me if I am wrong, but with 6to4 the identifer
to locator mapping comes from a single DNS lookup. The
identifer is not routeable over the core, but the ETR
locator is embedded in the identifier address so the
ETR discovery comes "for free".

The EID in DNS could be a 2002::/16 prefix, but it shouldn't assume the address
itself or the IPv4 embedded in it is routable.

Is 6to4 an example of LISP 2? Is it good enough to be

Well you can put 2002 addresses in DNS. So from a LISP point of view, it just a
mapping lookup on a string of bits.

considered as a long-term solution, or is it just a
baby-step to a fully jacked-up LISP deployment?

If you used IPv6 addresses as EIDs and IPv4 addresses as locators, then the 6to4 step would be an extra one you would not need. And I wouldn't want to use it because it adds an additional 20 bytes to the packet (as described from the sequence above).

Dino

_______________________________________________
RAM mailing list
RAM at iab.org
https://www1.ietf.org/mailman/listinfo/ram