Hi, I think the statements apply to different scenarios.
The sequence number can be used to match an echo request and an echo reply. But for UDP/TCP or any transport-layer communications, addresses (regardless of the src or dest) change could lead to communication interruption. Thanks, washam 2011/11/5 François-Xavier Le Bail <fx.leb...@yahoo.com>: > Hi, > > The RFC 4443 (Internet Control Message Protocol (ICMPv6) for the > Internet Protocol Version 6 (IPv6) Specification) states : > (http://tools.ietf.org/html/rfc4443#section-4.2) > [. . .] > "An Echo Reply SHOULD be sent in response to an Echo Request message > sent to an IPv6 multicast or anycast address. In this case, the > source address of the reply MUST be a unicast address belonging to > the interface on which the Echo Request message was received." > > The RFC 4942 (IPv6 Transition/Coexistence Security Considerations) states : > (http://tools.ietf.org/html/rfc4942#section-2.1.6) > 2.1.6. Anycast Traffic Identification and Security > [. . .] > "To avoid exposing knowledge about the internal structure of the > network, it is recommended that anycast servers now take advantage of > the ability to return responses with the anycast address as the > source address if possible." > > Even if it is "must" versus "recommended", It seems contradictory > for an anycast address. > > Please let me know your feedback. > > Thanks, > Francois-Xavier Le Bail > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
