There seems to be a difference in bandwidth usage when I run
tcpdump -e -w - | pv -a > /dev/null as opposed to running
For example, I saw a bandwidth usage of 150kbps using
nload but only 30kbps using
tcpdump. To rule out
pv, I've done the following:
# open a tmux session where tcpdump dumps all traffic into a file for 60 seconds $ tmux new-session -d -s tcpdump_60secs 'tcpdump -e -w tempfile' && sleep 60 && tmux kill-server $ wc -c tempfile # divide by 60, resulting in bytes per second
Any pointers to how
nload gets its bandwidth statistics will be appreciated.
Replicated on a clean Ubuntu 18.04 install, on a LXC proxmox container, tested with nload build using commit 8f92dc0.