[patch] BLIP sends packets for unknown PAN addresses back over the PPP link repeatedly

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What steps will reproduce the problem?
1. Set up a typical PppRouter.
2. Run tcpdump on the PPP interface.
3. Ping an address of a not-available/unknown PAN node from the host side.
4. Note how the ping requests are sent out the PPP interface, then received 
back on the same interface, routed right back out the PPP interface, received 
back etc. etc. until the TTL of the packet expires.

What is the expected output? What do you see instead?
Packets destined for a PAN address received from the PPP interface in TinyOS 
should not be routed back out the PPP interface. Doing so is both wasteful and 
interferes with traffic to actual nodes.

What version of the product are you using? On what operating system?
TinyOS-2.x trunk; Ubuntu 11.04.

Please provide any additional information below.
Due to the way the routing table get constructed with this setup, there is a 
need to apply a split-horizon to the routing/forwarding of packets received on 
the PPP link. Attached patch is a simple 2-liner (plus comment) to do this.

It could be argued that the decision as to whether split-horizon should be 
applied to a source interface should be abstracted out to an interface flag 
rather than a specific interface type, but given the nature and scope of TinyOS 
that seems slight overkill at this stage.

Original issue reported on code.google.com by jmatts...@dius.com.au on 6 Dec 2011 at 5:46

Attachments:

• tinyos-blip-ppp-split-horizon.patch

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Original comment by marku...@gmail.com on 19 Dec 2011 at 8:14

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Resolved in r5874.  I however put the logic into the interface-specific 
forwarding logic in PppRouter using the ForwardingEvents interface.

Original comment by sdh...@gmail.com on 18 Jan 2012 at 9:07

• Changed state: Fixed