the o bit was to state use dhcpv6 but not for addresses. it is not binary but ternary. /jim
> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Bernie Volz (volz) > Sent: Friday, May 27, 2005 8:56 AM > To: [EMAIL PROTECTED]; Ralph Droms (rdroms); > dhcwg@ietf.org; ipv6@ietf.org > Subject: RE: [dhcwg] RE: purpose of m/o bit > > We don't but it avoids issues with backwards compatibility (though I > don't believe that is a big issue yet). > > I think if we come to agreement on having no distinction between the > bits, we should deprecate one of the bits (O-bit?); though > for backwards > compatibility, we can't remove/reassign it until many years > from now (if > ever). > > - Bernie > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > > On Behalf Of [EMAIL PROTECTED] > > Sent: Friday, May 27, 2005 8:42 AM > > To: Ralph Droms (rdroms); dhcwg@ietf.org; ipv6@ietf.org > > Subject: [dhcwg] RE: purpose of m/o bit > > > > Ralph Droms <[EMAIL PROTECTED]> wrote: > > > > > Seems to me I'm hearing two requirements out of this thread: > > > > > > 1) Ability to indicate to a host "DHCP is not available on > > this link", > > > with the expectation that the host won't send any DHCP messages > > > > > > 2) Ability for a host to get all desired and available DHCP > > > configuration with a single DHCP message exchange > > > - if a host wants HCB, it sends an HCB request (Solicit) > > > and receives > > > HCB and/or ICB replies > > > - if a host wants ICB, it sends an ICB request > > > (Information-request) > > > and receives ICB replies > > > > > > 1 is a requirement in scenarios with limited resources (e.g., > > > wireless), where polling for DHCP is unacceptable. 2 is a > > > requirement to avoid timeout delays or other complexity in getting > > > ICB reply when > > > host would > > > prefer HCB reply. > > > > > > If I've got that right, we can meet the two requirements > > with a couple > > > of small updates to existing specs: > > > > > > 1) If an RA is received with the M and/or the O bit is set, DHCP > > > service is available over the link through which the RA > > > was received > > > (no differentiation between HCB and ICB DHCP) > > > > > > 2) If a DHCP server receives an HCB request (Solicit) but can only > > > supply an ICB, the server can respond with the ICB reply > > (note that > > > according RFC 3115, the server would respond with an "HCB-nak" > > > [Advertise containing only an error code]) > > > > > > In addition to meeting the requirements, these updates are > > mostly (if > > > not entirely) operationally compatible with existing clients and > > > servers. > > > > I completely agree with this analysis and support proceeding on this > > basis. But it does beg the question, why do we need two bits > > to signal a > > binary condition? > > > > -- Mat > > > > _______________________________________________ > > dhcwg mailing list > > dhcwg@ietf.org > > https://www1.ietf.org/mailman/listinfo/dhcwg > > > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
