|Summary:||Unable to filter packets by VLAN tag|
|Product:||Red Hat Enterprise Linux 6||Reporter:||Norman Elton <normelton>|
|Component:||libpcap||Assignee:||Michal Sekletar <msekleta>|
|Status:||CLOSED ERRATA||QA Contact:||Tomas Dolezal <todoleza>|
|Version:||6.4||CC:||emajorsi, msekleta, psklenar|
|Fixed In Version:||libpcap-1.4.0-4.20130826git2dbcaa1.el6||Doc Type:||Bug Fix|
Documentation for this issue is the same as for #1063328 Previously, running the "tcpdump" command with the filter expressioncontaining the keyword "vlan" produced unexpected output, as the filtergenerated by the libpcap Berkeley Packet Filter (BPF) compiler did notemploy BPF extensions. To fix this bug, libpcap has been amended and nowgenerates filters that use BPF extensions when appropriate. As a result,running "tcpdump" with filters containing "vlan" produces correct results.
|Last Closed:||2015-07-22 06:17:12 UTC||Type:||Bug|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
|Bug Depends On:|
|Bug Blocks:||1070830, 1159820|
Description Norman Elton 2013-11-01 17:41:39 UTC
Tcpdump drops all packets when filtering by VLAN tag. Works fine when reading packets from a file, but not when reading from a NIC. For example, this captures nothing: tcpdump -i eth15 -nnte vlan But this works as expected: tcpdump -i eth15 -nnte -w - | tcpdump -r - vlan Kernel information: # uname -a Linux blocto.safety.net.wm.edu 2.6.32-358.23.2.el6.x86_64 #1 SMP Sat Sep 14 05:32:37 EDT 2013 x86_64 x86_64 x86_64 GNU/Linux Tcpdump information: # rpm -q tcpdump tcpdump-4.0.0-3.20090921gitdf3cb4.2.el6.x86_64 Driver information: # ethtool -i eth15 driver: e1000e version: 2.1.4-k firmware-version: 5.10-2 bus-info: 0000:26:00.1 supports-statistics: yes supports-test: yes supports-eeprom-access: yes supports-register-dump: yes supports-priv-flags: no
Comment 2 Michal Sekletar 2013-11-08 09:10:07 UTC
This is not a bug in tcpdump itself but rather in libpcap. Reassigning there. Note that before doing something about this on libpcap side, some changes in kernel has to be introduced.
Comment 3 Michal Sekletar 2014-02-06 14:30:30 UTC
Just an quick update on the current status. Kernel part is done, now we can move to fixing libpcap.
Comment 4 Michal Sekletar 2014-11-04 12:36:51 UTC
Opened a pull request on github trying to address this. https://github.com/the-tcpdump-group/libpcap/pull/391 Feel free to join the discussion on github and also testing would be much appreciated. Thanks.
Comment 5 Michal Sekletar 2015-01-27 15:43:04 UTC
Comment 9 errata-xmlrpc 2015-07-22 06:17:12 UTC
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2015-1288.html