Pekka Savola wrote: > On Thu, 28 Feb 2002 [EMAIL PROTECTED] wrote: > > R1 (6to4 router) -- R2 (IPv4) -- R3 (IPv4) -- R4 > (relay router) > > > > Note: R1 is a pure 6to4 router; R2 and R3 are part of the > IPv4 cloud; R5 > > is a relay router. > > > > In the 6to4 model R1 and R4 need to have a 6to4 address. > From RFC 3056 I > > understand that these 6to4 addresses have to be configured on the > > interface between R1 and R2 (R4 and R3) respectively. I am > now puzzled > > between the following 2 observations: > > 1) I would also expect to have an IPv6 address configured > on R2's end of > > the R1-R2 interface. After all, only configuring an IPv6 > address on 1 of > > the routers connected to an interface would be a bit > strange? A similar > > remark holds for R3 on the R4-R3 interface. > > 2) However, no IPv6 address should be assigned to R2 (R3) > since R2 (R3) is > > only IPv4 capable? > > It's 6to4 _pseudo_ - interface :-). It's not assigned > (normally) on any > physical link. The only address you need between R1-R2 and > R3-R4 are IPv4 > addresses (from which, a 6to4 address may be derived from). >
In case that was not clear; the IPv6 address on R1 & R4 are assigned to the pseudo interface that forms a logical point-to-point tunnel over the physical interfaces with IPv4 addresses. Another way to look at it is to consider the IPv4 components to be the logical equivalent of a multi-point Layer-2 network (like frame relay or ATM) so the IPv4 wrapper becomes just another framing wrapper for the 2002::/16 IPv6 subnet. Tony -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
