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tinyos / tinyos-main

Main development repository for TinyOS (an OS for embedded, wireless devices).
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[blip] Deriving EUI64 from Dallas chip fails rarely on TelosB #138

Open tinyos-issues opened 11 years ago

tinyos-issues commented 11 years ago

Original author: marku...@gmail.com (April 30, 2012 13:51:48)

What steps will reproduce the problem?

  1. Install many nodes with UdpEcho. Let them run for a long time.
  2. Sniff the traffic.
  3. Observe weird link-local addresses like fe80::2126d45:5000:0 in wireshark. This should be from
  4. If multiple nodes fail to read the ID from the Dallas chip to derive the link-local address, all of them end-up with the same link-local address.
  5. pings result in DUP packets.

What is the expected output? What do you see instead? Expected output: proper link-local addresses like fe80:212:6d45:50e6:bb36. No DUP packets when pinging.

As a fall-back derive the link-local-address from TOS_NODE_ID?

Original issue: http://code.google.com/p/tinyos-main/issues/detail?id=135

bradjc commented 11 years ago

The value from the DS2411 should be cached in software so a node shouldn't lose its address. Also, it should return an error if the read fails. Issue #176 should make this code more clear.