Subject: RE: Manet flooding / broadcasting....

From: Scott Corson <[email-masked]>
Date: Sun, 20 Jan 2002 15:49:56 -0500

> P.S. Fred Templin and I previously proposed a method for flooding
> packets having the limited broadcast address (255.255.255.255)
> and low-numbered multicast addresses (224.0.0.x) to all MANET
> nodes, by encapsulating into a packet having the ALL_MANET_NODES
> address. (Search for message posted last March to May having
> "MANET addressing" in the subject.) The above discussion does not 
> include these addresses.

I went back and reread these conversations (mar/apr last year).  I think
that carrying multicast within this flooding capability could be a useful
near-term capability, and probably all that is needed for many small
networks.

Does anyone see problems with optionally flooding IP-in-IP-encapsulated
limited broadcast and multicast traffic in MANETs?  Using this approach I
assume a manet multicast sender has the option to encapsulate into this
"flooding tunnel" if you will.  Every stack that receives IP-in-IP sent to
the ALL_MANET_IPvX_NODES multicast address can decapsulate and process as
necessary, as well as forward the encapsulated packet as part of the
flooding algorithm as necessary.

Comments?

-Scott

---

From: [email-masked]
Date: Sun, 20 Jan 2002 21:24:37 -0800

Scott,

> flooding algorithm as necessary.

Yes, I agree that this encapsulation should be optional, and
is done *above* the MANET network layer.  It would be done by
an application that chooses to treat the MANET like an Ethernet.
(Some applications may not want to treat the MANET like an Ethernet.)
The MANET network layer should treat the limited broadcast address 
255.255.255.255 exactly as in RFC1812 (i.e., a packet with this address
should not be forwarded). For example, the MANET might *include* an 
actual Ethernet as one subnet, and 255.255.255.255 can be used by 
a MANET router to reach all other routers connected to that Ethernet,
or more generally to reach all neighboring routers.

Regards,
Richard