# Why so many dropped packets?



## pavlar (Oct 20, 2021)

FreeBSD 13.0
tcpdump -i igb2
.............
1884 packets captured
6933 packets received by filter
2575 packets dropped by kernel

tcpdump -i igb3
..........
307 packets captured
12478 packets received by filter
9916 packets dropped by kernel


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## a6h (Oct 23, 2021)

Disable DNS queries (-n) and promiscuous mode (-p), increase the buffer size (-B) and try again. e.g.

`tcpdump -p -n -B 4096`

Note:
The "-B" option in the FreeBSD and GNU/Linux sets the buffer_size. But in the OpenBSD, it sets the "drop action", i.e. pass, capture and drop. Keep that in mind.


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