I captured a packet using the command tethereal -i bond0 -R "smpp" -w /tmp/file. When I viewed the file its shows Malformed Packet on submit_sm. Why is that so?
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asked 20 May '11, 17:06
edited 21 May '11, 07:07
Although it's not 100% certain without looking at the actual trace, one possible explanation might be:
A smpp protocol PDU can be split across multiple tcp segments (and therefor frames). When you use a (display) filter like smpp, tshark will only show the frame in which the reassembly completed (in which the last segment of the PDU was found). So only that frame is saved in the capture file. When you reopen the capture file, the first fragment(s) of the smpp PDU are not found and you end up with a broken PDU, hence the "Malformed Packet"
(BTW 'tethereal' is realy old (at least 5 years), you might want to upgrade to the latest wireshark/tshark version)
answered 20 May '11, 23:17