NAME

nethogs - Net top tool grouping bandwidth per process

SYNOPSIS

nethogs [-V] [-h] [-x] [-d seconds] [-v mode] [-c count] [-t] [-p] [-s] [-a] [-l] [-f filter] [-C] [-b] [-g period] [-P pid] [device(s)]

DESCRIPTION

NetHogs is a small 'net top' tool. Instead of breaking the traffic down per protocol or per subnet, like most such tools do, it groups bandwidth by process - and does not rely on a special kernel module to be loaded. So if there's suddenly a lot of network traffic, you can fire up NetHogs and immediately see which PID is causing this, and if it's some kind of spinning process, kill it.

Options

-V: prints version.
-h: prints available commands usage.
-x: bughunt mode - implies tracemode.
-d: delay for update refresh rate in seconds. default is 1.
-v: view mode (0 = kB/s, 1 = total kB, 2 = total bytes, 3 = total MB, 4 = MB/s, 5 = GB/s). default is 0.
kB: 2e10 bytes, MB: 2e20 bytes, GB: 2e30 bytes
-c: number of updates. default is 0 (unlimited).
-t: tracemode.
-p: sniff in promiscuous mode (not recommended).
-s: sort output by sent column.
-l: display command line.
-a: monitor all devices, even loopback/stopped ones.
-C: capture TCP and UDP.
-b: Display the program basename.
-g: garbage collection period in number of refresh. default is 50.
-P: Show only processes with the specified pid(s).
-f: EXPERIMENTAL: specify string pcap filter (like tcpdump). This may be removed or changed in a future version.

device(s) to monitor. default is all interfaces up and running excluding loopback

INTERACTIVE CONTROL

q: quit
s: sort by SENT traffic
r: sort by RECEIVED traffic
l: display command line
b: display the program basename
m: switch between total (KB, B, MB) and throughput (KB/s, MB/s, GB/s) mode

RUNNING WITHOUT ROOT

In order to be run by an unprivileged user, nethogs needs the cap_net_admin and cap_net_raw capabilities. Additionally, to display process names, cap_dac_read_search and cap_sys_ptrace capabilities are required. These can be set on the executable by using the setcap(8) command, as follows:

sudo setcap "cap_net_admin,cap_net_raw,cap_dac_read_search,cap_sys_ptrace+pe" /usr/local/sbin/nethogs

Notes

1. When using the -P <pid> option, in a case where a process exited (normally or abruptly), Nethogs does not track that it exited. So, the operating system might create a new process (for another program) with the same pid. In this case, this new process will be shown by Nethogs.

AUTHOR

Written by Arnout Engelen <arnouten@bzzt.net>.