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#152 libpcap doesn't find VLAN packets

Git head
closed
nobody
None
5
2013-11-20
2011-08-14
David Ford
No

tcpdump 4.2.0rc1
libpcap 1.2.0rc1
Linux kernel 3.0.1
Linux headers 2.6.38

>> tcpdump -ennlxx -i tap0 vlan
results in zero packets ever matching

>> tcpdump -ennlxx -i tap0 ether src 00:e0:81:27:68:08
shows all the applicable packets, with the VLAN tag decoded

e.g.
06:04:38.101881 00:e0:81:27:68:08 > 2e:d2:07:2c:5f:22, ethertype 802.1Q (0x8100), length 96: vlan 200, p 0, ethertype IPv4, 192.168.26.1.137 > 192.168.26.240.137: NBT UDP PACKET(137): QUERY; REQUEST; UNICAST
0x0000: 2ed2 072c 5f22 00e0 8127 6808 8100 00c8
0x0010: 0800 4500 004e d493 4000 4011 afc9 c0a8
...

referencing http://netoptimizer.blogspot.com/2010/09/tcpdump-vs-vlan-tags.html, the libpcap configure indicated "yes" for tpacket_aux. additionally i was under the impression that the needed changes were applied for this release.

Discussion

  • Denis Ovsienko

    Denis Ovsienko - 2013-11-20
    • status: open --> closed
    • Group: --> Git head
     

  • Denis Ovsienko

    Denis Ovsienko - 2013-11-20

    Administrators of the "libpcap" SourceForge project have superseded this tracker item (formerly artifact 3391397, now bug 152) with issue 154 of the "libpcap" GitHub project.

     
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