Hi Fred, In your reply, > They not only come from MAC addresses, but from random number > generators...
I didn't understand "They" apply to 64-bit of link_local address or 64-bit of autoconf/dhcp address or both? What I understood is: RFC 3972 contradicts with RFC 2464. Or both the methods are correct for ETHERNET for Link-local and autoconf addresses? RFC 4291 asks to refer the Link layer specific RFC for the 64-bit Interface Id of the link-local address - which is 2464 (for Ethernet). So thats the confusion I have. Or the RFC 3972 doesn't apply to the 64-bits of the Link-local addresses, but it applies to 64-bit of the addresses configured via DHCPv6 and/or stateless auto-conf RFCs 3315, 4862? Regards, Parav Pandit --- On Thu, 4/15/10, Fred Baker <f...@cisco.com> wrote: > From: Fred Baker <f...@cisco.com> > Subject: Re: deriving MAC address from destination Link local address without > Neighbor discovery > To: "Parav Pandit" <paravpan...@yahoo.com> > Cc: ipv6@ietf.org > Date: Thursday, April 15, 2010, 12:10 PM > There has been some water that passed > under that bridge. They not only come from MAC addresses, > but from random number generators and cryptographic > algorithms - and can simply be numbers assigned by > administrators. > > In addition to > > 2464 Transmission of IPv6 Packets over Ethernet Networks. > M. Crawford. > December 1998. (Format: TXT=12725 > bytes) (Obsoletes RFC1972) (Status: > PROPOSED STANDARD) > > take a look at > > http://www.ietf.org/rfc/rfc3315.txt > 3315 Dynamic Host Configuration Protocol for IPv6 (DHCPv6). > R. Droms, > Ed., J. Bound, B. Volz, T. Lemon, > C. Perkins, M. Carney. July 2003. > (Format: TXT=231402 bytes) > (Updated by RFC4361, RFC5494) (Status: > PROPOSED STANDARD) > > http://www.ietf.org/rfc/rfc3972.txt > 3972 Cryptographically Generated Addresses (CGA). T. Aura. > March 2005. > (Format: TXT=51473 bytes) (Updated > by RFC4581, RFC4982) (Status: > PROPOSED STANDARD) > > http://www.ietf.org/rfc/rfc4291.txt > 4291 IP Version 6 Addressing Architecture. R. Hinden, S. > Deering. > February 2006. (Format: TXT=52897 > bytes) (Obsoletes RFC3513) (Status: > DRAFT STANDARD) > > http://www.ietf.org/rfc/rfc4862.txt > 4862 IPv6 Stateless Address Autoconfiguration. S. Thomson, > T. Narten, > T. Jinmei. September 2007. > (Format: TXT=72482 bytes) (Obsoletes > RFC2462) (Status: DRAFT STANDARD) > > http://www.ietf.org/rfc/rfc4941.txt > 4941 Privacy Extensions for Stateless Address > Autoconfiguration in > IPv6. T. Narten, R. Draves, S. > Krishnan. September 2007. (Format: > TXT=56699 bytes) (Obsoletes > RFC3041) (Status: DRAFT STANDARD) > > > On Apr 14, 2010, at 10:55 PM, Parav Pandit wrote: > > > Hi, > > > > As per RFC 2464, Link local address for Ethernet based > interfaces are based on the EUI-64 (derived from the MAC > address). > > > > I have #3 questions based on this. > > > > In this case, > > when one Ethernet based host(from its link-local > source) tries to ping the other Ethernet based host, it > knows the Mac address implicitly (from the Link local > address). > > > > 1. Why is it required to explicitly do the Neighbor > discovery for the link-local addresses? > > RFC 4861 says to do the neighbor discovery even for > link-local addresses. > > Correct me if my understanding is incorrect. > > > > 2. Does it mean that in Ethernet networks, interface > can have only one Link-local address? If not then we violate > the RFC 2464. > > > > 3. Does RFC 4941 Privacy extension for autoconf apply > to Ethernet interfaces? > > > > Regards, > > Parav Pandit > > > > > > > > > > > -------------------------------------------------------------------- > > IETF IPv6 working group mailing list > > ipv6@ietf.org > > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > > > -------------------------------------------------------------------- > > http://www.ipinc.net/IPv4.GIF > > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
