Here are comments on draft-moore-ipv6-optimistic-dad-04.txt. I have one relatively-substantial comment and several editorial ones.
The relatively-substantial comment is: I don't see the strong need for the unsolicited neighbor advertisements described in Section 3.1: * (adds to 7.2.6) The Optimistic node MAY send an unsolicited Neighbour Advertisement to All Nodes when it first configures an address. The Override flag on this advertisement MUST be set to 0. * (adds to 7.2.6) The Optimistic node SHOULD send an unsolicited NA to All Nodes when it completes DAD. The Override flag on this advertisement SHOULD be set to 1. In particular, I don't understand why we SHOULD send the unsolicited NA in the latter case. Other (mostly) editorial comments. 1. the draft contain many acronyms without or before (clearly) showing the original term. those include: DAD, ND, SAA, SLLAO, RS, RA, ON, NC, NS, NA, MN, and LLAO. 2. The second paragraph of Introduction contains an incomplete sentence. ... Disruption is minimized by limiting nodes' participation in Neighbour Discovery while their addresses are still Tentative, (or perhaps the comma should actually be a period) 3. One definition in Section 1.3 is not well defined (IMO): Well-Distributed Address - Address suffixes used for Optimistic DAD should be well distributed, eg: there should be an equal probability of any given suffix occuring. This minimizes the probability of an address collision. I would say this is a requirement, not a definition. I'd also like to point out "well distributed" is not really clear in a definition, but this is probably a minor issue (I can live with the wording). 3. In section 2, * Never using a Tentative address ... .... Another address, or the unspecified address, may be used, or the RS may be send without an SLLAO. s/may be send/may be sent/ 4. In section 2. When the MN wants to contact another neighbour, but it cannot because ... I guess MN stands for "mobile node" (see my first comment BTW), but I don't see why we need to use this word here. As far as I can see, there is nothing specific to a mobile node in this context. 5. In the same paragraph, ...The router should then provide the MN with a ICMP redirect, which may ... s/a ICMP/an ICMP/ 6. In Section 3.2 * (modifies 5.5) If an initial suffix is not supplied, a new suffix SHOULD be generated as per "Address Generation" below. What does "initial suffix" mean? RFC2462 (or its bis) doesn't use this wording. 7. In Section 3.2 * (modifies 5.4.5) ... If the address is a link-local address formed from a fixed interface identifier, the interface SHOULD be disabled. Otherwise, if the address was What does "a fixed interface identifier" mean? (e.g.) An interface identifier derived from a hardware address like EUI-64? FYI, the latest rfc2462bis draft contains the following sentence in Section 5.4.5: If the address is a link-local address formed from an interface identifier based on the hardware address (e.g., EUI-64), the interface SHOULD be disabled. 8. In Section 3.3 * If the interface offers a method to create a supposedly globally unique IPv6 address, this address MAY be used for the initial attempt. This is not very clear to me. What exactly does "a supposedly globally unique" mean? For instance, is an EUI-64 based IPv6 address supposedly globally unique? 9. In Section 3.3 * In order to minimize the effect of DoS attacks, a delay of at least RETRANS_TIMER (as used in [RFC2461]) milliseconds MUST be introduced between attempts if DAD has already failed more than once. An exponential backoff SHOULD be used. Does more than once mean "two times or more" (the answer should be yes in the literal sense)? If so, why don't we need a delay after the first failure? 10. In Section 3.4 ... In order to minimize the probability of an undetected address collision, it would seem prudent to always configure and check the link-local address for any given suffix as well as checking the actual address being configured. I'm not really sure what "the actual address" means. Do you mean "non link-local address"? 11. In Section 4.2 ... An NA with O=0,S=0 and no LLAO may [Note 1], however cause the NC entry to be set to STALE, causing NUD to be performed on the address. Shouldn't the "no LLAO" really be "with LLAO"? If not, what is the purpose of this NA (O=0,S=0, no LLAO)? JINMEI, Tatuya Communication Platform Lab. Corporate R&D Center, Toshiba Corp. [EMAIL PROTECTED] -------------------------------------------------------------------- IETF IPv6 working group mailing list [EMAIL PROTECTED] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------