Subject: [6lo] 802.15.4 source/target address option(s) inside NA/NS/RS

From: Alexander Aring <[email-masked]>
Date: Mon, 22 Feb 2016 10:30:19 +0100

Hi,

[0] describes the format between short and extended address for address
options inside NA/NS.

First question:
MUST 802.15.4 6LoWPAN _always_ have two address option fields inside
these messages?

What in case of short address and 0xfffe (unspec)?
Should this also be included or a "extended address" option field only and don't
add a short address option field then?

Also what is if node has 0xffff as short address and it's invalid, should insert
0xfffe there or don't add a option address for short address then?
(btw: 0xffff as source address is valid, because 802.15.4 has it as MIB default,
I think it's not used then, like 0xfffe).

When I get 0xfffe address for L2 "destination address" address I would ignore
it and run some fallback to the extended-addr.

Next question is:
Must this also be included inside RS messages? I think yes, everywhere which
has address options inside.

Last question is:
Currently I try to add short address handling inside the linux kernel ipv6 neighbor
discovery implementation. They filter stuff when target/source option fields are
more than once placed inside NA/NS/RS.

I have some general question here:

Can IPv6 (e.g. over Ethernet) has multiple address options here as well?

Two Ethernet L2 addresses (MAC) for one L3 address (IP)? If this is true, then I
could try to implement a more generic way to handle multiple addresses for one
IP address.

Thanks in advance.

- Alex

[0] https://tools.ietf.org/html/rfc4944#section-8