On Thu, May 09, 2019 at 06:46:02PM +0000, Mankamana Mishra (mankamis) wrote: > On May 9, 2019, at 11:42 AM, Jeffrey Haas > <[email protected]<mailto:[email protected]>> wrote: > > Section 7.1: > > The lengths of the various fields and their consistency should be spelled > > out in more detail. > > > > For example, a source could be 0 for (*,G), or should be the length of an > > IPv4 or IPv6 host address (32/128). Other lengths likely do not make sense. > > From > 7.1.1<https://tools.ietf.org/html/draft-ietf-bess-evpn-igmp-mld-proxy-02#section-7.1.1> > Constructing the Selective Multicast Ethernet Tag route > > > The Multicast Source length MUST be set to length of multicast source > address in bits. In case of a (*, G) Join, the Multicast Source > Length is set to 0. > > > in case of (*,G) join , source length would be 0. and it does say in this > section.
It does not specify that 32 or 128 is the only other two useful options though. Basically, the point is that in the absence of text that "this is a host", the implication is "this might be a subnet". For example, if the length is 24, even properly encoded on the wire for that length, what do you do with 24 bits of a source? > > The length of a multicast group also likely should be a "host" length - > > 32/128. > > > > For the source and the group, it is likely an error if the lengths do not > > agree. E.g. S may be 0, but when 32 or 128 the group must be 32 or 128 > > respectively. > > Do you mean, draft should spell out different possible errored length ? or > may be statement similar to https://tools.ietf.org/html/rfc6514 would be good > enough ? Consider 6514, section 4.3: : The Multicast Source field contains the C-S address. If the : Multicast Source field contains an IPv4 address, then the value of : the Multicast Source Length field is 32. If the Multicast Source : field contains an IPv6 address, then the value of the Multicast : Source Length field is 128. So, yes, that would be what I was expecting here. > > The originator router also should likely be a host length, although I'm a > > bit unclear what the intent of the contents of this field should be. Is > > this intended to be a loopback? If so, how does one choose it among > > several, if more than one is available? Should the length of the originator > > also agree with the S,G fields? > > Do you mean (S,G) len should be driving factor Originator len / IP ? If I have ipv4 (S,G), is it reasonable that I got that from a router that is via IPv6? > > The flags field is somewhat confusing when the addresses are IPv6 and thus > > the procedures are expected to be for MLD rather than IGMP. The draft as a > > whole, in spite of its title, is worded heavily toward IGMP. I would > > suggest requesting some appropriate review to help normalize the terminology > > here. However, the flags field should be clarified for MLD cases. > > This is being already addressed in next version. Thanks. -- Jeff _______________________________________________ BESS mailing list [email protected] https://www.ietf.org/mailman/listinfo/bess
