[Olsr-dev] Duplicate LQ_TC_MESSAGE in OLSR packets

[Hannes Gredler]

patrick,

looks to me like a bug in the fisheye implementation where
olsrd sends the same message with a different ttl modulation.

seems TC-LQ message #3 is redundant.

11:12:36.264129 IP (tos 0x10, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 128)
    193.238.159.17.698 > 193.238.159.255.698: OLSR, seq 0xc17f, length 100
        TC-LQ Message (202), originator 193.238.159.17, ttl 1, hop 0
          vtime 496.000s, msg-seq 0x3b65, length 24
            advertised neighbor seq 0x0029
              neighbor 193.238.156.2, link-quality 100.00%, neighbor-link-quality 100.00%
        TC-LQ Message (202), originator 193.238.159.17, ttl 2, hop 0
          vtime 496.000s, msg-seq 0x3b66, length 24
            advertised neighbor seq 0x0029
              neighbor 193.238.156.2, link-quality 100.00%, neighbor-link-quality 100.00%
>       TC-LQ Message (202), originator 193.238.159.17, ttl 1, hop 0
>         vtime 496.000s, msg-seq 0x3b67, length 24
>           advertised neighbor seq 0x0029
>             neighbor 193.238.156.2, link-quality 100.00%, neighbor-link-quality 100.00%
        TC-LQ Message (202), originator 193.238.159.17, ttl 8, hop 0
          vtime 496.000s, msg-seq 0x3b68, length 24
            advertised neighbor seq 0x0029
              neighbor 193.238.156.2, link-quality 100.00%, neighbor-link-quality 100.00%

/hannes

On Fri, Jun 08, 2007 at 04:33:33PM -0700, Patrick McCarty wrote:
| Hi folks,
| 
| I was doing some network traffic inspection today and noticed that
| there appear to be duplicate LQ_TC_MESSAGE types in the OLSR traffic.
| (Packet dump below)
| 
| Anyway.. if you compare the data segments for these messages, they are
| identical.
| 
| Seems a sanity check is needed.. I'm trying to figure out where that
| might need to be implemented.
| 
| I suspect that this is the case for LQ_HELLO messages as well, but
| since the interval I have configured for those is not as often, the
| problem is hidden. Or for that matter, any other message type....
| 
| All that said... this isn't really causing any obvious problems..
| Aside from the exponentially increased network traffic. (And I suppose
| increased processing overhead on the receivers)
| 
| Any thoughts?
| 
| Thanks,
| 
| Patrick
| 
| ------
| Packet Length: 196 bytes
| Packet Sequence Number: 34717
| 
| Message Type: LQ_TC_MESSAGE (202)
| Validity Time: 248.000 (in seconds)
| Message Size: 24 bytes
| Originator Address: 192.168.0.103 (192.168.0.103)
| Time to Live: 254
| Hop Count: 0
| Message Sequence Number: 42674
| Data (12 bytes)
| 
| (Then about 10 more of these per packet)
| 
| -----
| Full dump
| 
| 0000   ff ff ff ff ff ff 00 0c 29 8e 7e a4 08 00 45 10  ........).~...E.
| 0010   00 e0 00 00 40 00 40 11 b7 46 c0 a8 00 67 c0 a8  (spam-protected)@..F...g..
| 0020   00 ff 02 ba 02 ba 00 cc db e1 00 c4 87 9d ca fb  ................
| 0030   00 18 c0 a8 00 67 fe 00 a6 b2 00 0b 00 00 ac 10  .....g..........
| 0040   42 01 ff ff 00 00 ca fb 00 18 c0 a8 00 67 01 00  B............g..
| 0050   a6 b4 00 0b 00 00 ac 10 42 01 ff ff 00 00 ca fb  ........B.......
| 0060   00 18 c0 a8 00 67 02 00 a6 b7 00 0b 00 00 ac 10  .....g..........
| 0070   42 01 ff ff 00 00 ca fb 00 18 c0 a8 00 67 01 00  B............g..
| 0080   a6 bd 00 0b 00 00 ac 10 42 01 ff ff 00 00 ca fb  ........B.......
| 0090   00 18 c0 a8 00 67 04 00 a6 be 00 0b 00 00 ac 10  .....g..........
| 00a0   42 01 ff ff 00 00 ca fb 00 18 c0 a8 00 67 01 00  B............g..
| 00b0   a6 c0 00 0b 00 00 ac 10 42 01 ff ff 00 00 ca fb  ........B.......
| 00c0   00 18 c0 a8 00 67 02 00 a6 c2 00 0b 00 00 ac 10  .....g..........
| 00d0   42 01 ff ff 00 00 ca fb 00 18 c0 a8 00 67 01 00  B............g..
| 00e0   a6 c4 00 0b 00 00 ac 10 42 01 ff ff 00 00        ........B.....

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