netdev - Re: Packets being dropped somewhere in the kernel, between iptables and packet capture layers

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Message-ID: <59bc1935-a3b3-dcf8-2db1-f9a90bd348d4@nh2.me>
Date:   Tue, 29 Jan 2019 01:45:44 +0100
From:   Niklas Hambüchen <mail@....me>
To:     netdev@...r.kernel.org
Cc:     Florian Westphal <fw@...len.de>
Subject: Re: Packets being dropped somewhere in the kernel, between iptables
 and packet capture layers

> Some DNS requests on my machine take 5 seconds when a specific network interface is used.

My big apologies for the confusion. I have found the reason.

There was a scripted

     tc qdisc add dev enp3s0 root netem loss 5%

in effect that I wasn't aware of while investigating.
This dropped 5% of the packets, and also explains why it was on that interface only.

Well, at least I know very well now at which level `tc` operates.

My bad, and sorry for the noise.