Thanks for the comments. We’ll bring this up in the meeting but I can’t address your comments until next week.
Some points: (1) Packets are “control-plane” encapsulated to the Map-Resolver, so the text is correct. (2) The WG had decided at some point to not include the NAT-traversal document because its not a WG document. (3) Your comments about clarifying text is valuable and IMO should go in. Thanks for that. Dino > On Nov 16, 2017, at 12:34 AM, Alberto Rodriguez-Natal > <rodriguezna...@gmail.com> wrote: > > Hi all, > > Wanted to send this before the meeting on Friday. I just completed a > review of 6833bis, you can find my comments below. Like last time, > extracts from the draft are copied and followed by my comments. > > Thanks, > Alberto > > > > > Map-Resolver: A network infrastructure component that accepts LISP > Encapsulated Map-Requests, > > • [AR] We could remove "Encapsulated" and just use "Map-Requests". > A Map-Resolver may accept non-encapsulated Map-Requests as well. > > Map-Register message: A LISP message sent by an ETR to a Map-Server > to register its associated EID-Prefixes. In addition to the set of > EID-Prefixes to register, the message includes one or more RLOCs to be > used by the Map-Server when forwarding Map-Requests (re-formatted as > Encapsulated Map-Requests) received through the database mapping > system. > > • [AR] This may give the impression that the RLOCs on the > Map-Register are only to forward Map-Requests, which is not the case > in proxy-reply mode. I would suggest we rephrase this text as follows: > "In addition to the set of EID-Prefixes to register, the message > includes one or more RLOCs to be used to reach the ETR. The Map-Server > uses these RLOCs when it has to forward Map-Requests (potentially > re-formatted as Encapsulated Map-Requests) received through the > database mapping system." > > Map-Notify message: A LISP message sent by a Map-Server to an ETR > > • [AR] I would replace "ETR" with "xTR" so we cover the PubSub > behavior as well. > > For definitions of other terms -- notably Map-Request, Map-Reply, > Ingress Tunnel Router (ITR), and Egress Tunnel Router (ETR) -- please > consult the LISP specification [I-D.ietf-lisp-rfc6830bis]. > > • [AR] I think that the definitions for Map-Request and Map-Reply > should be moved here, and probably we should include the definition > for Map-Notify-Ack as well. 6830bis should reference 6833bis for > control-plane messages, not the other way around. > > A Map-Register message contains a list of EID-Prefixes plus a set of > RLOCs that can be used to reach the ETR when a Map-Server needs to > forward a Map-Request to it. > > • [AR] Since proxy-reply is a common case, I'd not constrain the > meaning of the RLOCs in the Map-Register. I'd remove the last part of > the sentence that says "when a Map-Server needs to forward a > Map-Request to it." > > A Map-Resolver receives Encapsulated Map-Requests from its client ITRs > and uses a mapping database system to find the appropriate ETR to > answer those requests. > > • [AR] A MR can receive Map-Requests that don't come from ITR > and/or that are not encapsulated. If we don't want to change the text, > at least I'd add at the beginning: "In a common scenario, a > Map-Resolver..." > > Note that while it is conceivable that a non-LISP-DDT Map-Resolver > could cache responses to improve performance, > > • [AR] The discussion on caching or not at the Map-Resolver goes > beyond DDT. We could rephrase this removing the mention to > "non-LISP-DDT". > > The LISP UDP-based messages are the Map-Request and Map-Reply > messages. When a UDP Map-Request is sent, the UDP source port is > chosen by the sender and the destination UDP port number is set to > 4342. When a UDP Map-Reply is sent, the source UDP port number is set > to 4342 and the destination UDP port number is copied from the source > port of either the Map-Request or the invoking data packet. > > • [AR] I would remove the first sentence and re-phrase this > paragraph as follows: "When a UDP LISP control message is sent and is > not a direct reply to a previous control message, the UDP source port > is chosen by the sender and the destination UDP port number is set to > 4342. When a UDP LISP control message is sent as a direct reply to a > previous message, the source UDP port number is set to 4342 and the > destination UDP port number is either set to 4342 or copied from the > source port of the invoking LISP control message. See the following > subsections for details." > > The UDP checksum is computed and set to non-zero for Map-Request, > Map-Reply, Map-Register, and Encapsulated Control Message (ECM) > control messages. > > • [AR] Shouldn't it be computed for all LISP control messages? > > EID-Prefix: This prefix is 4 octets for an IPv4 address family and 16 > octets for an IPv6 address family. When a Map-Request is sent by an > ITR because a data packet is received for a destination where there is > no mapping entry, the EID-Prefix is set to the destination IP address > of the data packet, and the 'EID mask-len' is set to 32 or 128 for > IPv4 or IPv6, respectively. > > • [AR] We should probably rephrase this to don't limit it to IPv4/6 > > For the latter two cases, the destination IP address used for the > Map-Request is one of the RLOC addresses from the Locator-Set of the > Map-Cache entry. > > • [AR] To refresh map-caches before TTL expiration, the > destination IP of the Map-Request can be the address of the Map-Server > if in proxy-reply. This should be considered here. > > If the ITR erroneously provides no ITR-RLOC addresses, the Map-Replier > MUST drop the Map-Request. > > • [AR] This could probably be a SHOULD since we use AFI = 0 as > ITR-RLOC to unsubscribe in PubSub. > > EID-Prefix: This prefix is 4 octets for an IPv4 address family and 16 > octets for an IPv6 address family. > > • [AR] We should mention the possibility for address families > other than IPv4/6. > > The RLOCs in the Map-Reply are globally routable IP addresses of all > ETRs for the LISP site. > > • [AR] We should remove "globally" here. Maybe also add a > "Generally" at the beginning since we might have LCAFs with AFI = 0 > (LISP-VPN encoding of Home-IID for instance). > > For example, a requester with two cached EID-Prefixes that are covered > by a Map-Reply containing one less-specific prefix replaces the entry > with the less-specific EID-Prefix. > > • [AR] Not sure if I follow here. Does this mean that a > less-specific received in a Map-Reply will erase from the map-cache > previously cached more-specifics that are covered by the > less-specific? > > When more than one EID-Prefix is returned, all SHOULD use the same > Time to Live value so they can all time out at the same time. When a > more-specific EID-Prefix is received later, its Time to Live value in > the Map-Reply record can be stored even when other less-specific > entries exist. > > • [AR] We should explain in which cases a more-specific can be > received later. > > The Locator-Set MUST be sorted in order of ascending IP address where > an IPv4 locator address is considered numerically 'less than' an IPv6 > locator address. > > • [AR] LCAF addresses (maybe with AFI=0) should be discussed here as well. > > Nonce: This 8-octet 'Nonce' field is set to 0 in Map-Register messages. > > • [AR] Since there may be future cases that benefit from having a > non-zero nonce on the Map-Register, I would suggest to rephrase this > sentence to add a CAN. > > E: This is the to-ETR bit. When set to 1, the Map-Server's intention > is to forward the ECM to an authoritative ETR. > > • [AR] Can M and E be set at the same time? > > LCM: The format is one of the control message formats described in > this section. At this time, only Map-Request messages are allowed to > be encapsulated. > > • [AR] Shall we mention the NAT traversal draft? > > A Map-Server's configuration must also include a list of the > EID-Prefixes for which each ETR is authoritative. > > • [AR] There may be certain cases where this does not need to be > pre-configured. I suggest we replace the "must" with a "should". Note > that this requirement is already a "should" in section 6. > > See [I-D.ietf-lisp-rfc6830bis] for details on how the Map-Server sets > certain flags (such as those indicating whether the message is > authoritative and how returned Locators should be treated) when > sending a Map-Reply on behalf of an ETR. > > • [AR] It may be useful to discuss at least some of those details here. > > _______________________________________________ > lisp mailing list > lisp@ietf.org > https://www.ietf.org/mailman/listinfo/lisp _______________________________________________ lisp mailing list lisp@ietf.org https://www.ietf.org/mailman/listinfo/lisp
