>> I think 20 bits should be already be more than enough. For simplicity, > I would >> just go for 64 bits. > > Appreciate the quick reply. Note BrianC already noted that 20 bits will > not suffice by saying "It puts you into birthday-paradox territory on a > LAN with a few hundred nodes.". His email is at the URL below. > > http://www.ietf.org/mail-archive/web/ipv6/current/msg14835.html > > We can go for a 62 bits long nonce in the Nonce Option. Can't pick 64 > because the Nonce Option will then not end in an 8-byte boundary. See > the details from RFC 3971 below.
I think you mean 48 bits. Ole > > Regards, > > Hemant > > 5.3.2. Nonce Option > > The purpose of the Nonce option is to make sure that an advertisement > is a fresh response to a solicitation sent earlier by the node. The > format of this option is described in the following: > > 0 1 2 3 > 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > | Type | Length | Nonce ... | > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | > | | > . . > . . > | | > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > > Type > > 14 > > Length > > The length of the option (including the Type, Length, and Nonce > fields) in units of 8 octets. > > Nonce > > A field containing a random number selected by the sender of the > solicitation message. The length of the random number MUST be at > least 6 bytes. The length of the random number MUST be selected > so that the length of the nonce option is a multiple of 8 octets. > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > [email protected] > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
