Subject: [Roll] Proposed new multicast group for AODV-RPL

From: Charlie Perkins <[email-masked]>
Date: Sun, 17 Apr 2022 11:23:22 -0700

Hello folks,

AODV-RPL messages could possibly be confusing to nodes that implement 
other protocols with MOP==4, and so we propose to create a new multicast 
group, perhaps called "All-AODV-RPL-nodes".  Nodes joining that 
multicast group MUST implement AODV-RPL and in particular have the 
ability to process and transmit RREQ and RREP messages.  AODV-RPL does 
not place any requirement on other nodes using MOP==4.

This is an efficient way of resolving a possible issue for other devices 
implementing RPL protocols with MOP==4.  I had originally thought that 
such other implementations would simply drop packets with unrecognized 
options.  But, as it turns out, that is not what RFC 6550 specifies.  I 
still think that good implementations would not forward unrecognized 
AODV-RPL options, but there is ambiguity on this point.  Moreover, 
without a new multicast group, it is possible to imagine implementations 
that would mix AODV-RPL options with other non-AODV-RPL options.  That 
would be more likely to cause errors.

Regards,
Charlie P.