I'm seeing very high RX dropped
packets in the output of ifconfig
: Thousands of packets per second, an order of magnitude more than regular RX packets
.
wlan0 Link encap:Ethernet HWaddr 74:da:38:3a:f4:bb
inet addr:192.168.99.147 Bcast:192.168.99.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:31741 errors:0 dropped:646737 overruns:0 frame:0
TX packets:18424 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:90393262 (86.2 MiB) TX bytes:2348219 (2.2 MiB)
I'm testing WiFi dongles. Both have this problem, and the one with the higher drop rate actually performs better in ping floods. The one with low dropped packets suffers from extreme Ping RTTs, while the other never skips a beat.
- What does Linux consider a dropped packet?
- Why am I seeing so many of them?
- Why doesn't it seem to affect performance?
There are lots of questions around with answers that say a dropped packet could be one of the following but that doesn't help me very much, because those possibilities don't seem to make sense in this scenario.
Best Answer
Packet Dropped seen from
ifconfig
could be due to many reasons, you should dig deeper into NIC statistics to figure out real reason. Below are some general reasonsLook at the output of
ethtool -S wlan0
iwconfig wlan0
and the content of
/proc/net/wireless
for any further information.