In your previous mail you wrote: As per ND specification the Neighbor Advertisement message contains "O" Flag (OverRide flag).
=> the "O" flag is mainly about the link-layer address. What is the purpose of this flag. => this flag says if the cached link-layer address should be overrided by a new one or not. Or when the nodes is supposed set this Flag. => always when not in the following cases. Or when the nodes are not supposed to set this flag. => when the responder acts as a proxy or for an anycast address, i.e. when there can be more than one valid responder. The RFC 2461 has an explicit SHOULD/SHOULD NOT in the definition of the flag. I suppose whenever the receiver finds a difference between the sent link address and the address what it has in its ND cache it can modify the value. => no, look at the state machine in appendix. You should not do what you'd like (so there are some MUSTs) because ND should be determinitisc. Why is this extra bit...? => to provide advertisements for proxies/anycasts in a deterministic way. Please reread RFC 2461, this part is pretty clear! Regards [EMAIL PROTECTED] -------------------------------------------------------------------- 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] --------------------------------------------------------------------
