1. Nload
Nload is a commandline tool that allows users to
monitor the incoming and outgoing traffic separately. It also draws out a
graph to indicate the same, the scale of which can be adjusted. Easy
and simple to use, and does not support many options.
So if you
just need to take a quick look at the total bandwidth usage without
details of individual processes, then nload will be handy.
$ nload
Installing Nload - Fedora and Ubuntu have got it in the default repos. CentOS users need to get nload from Epel repositories.
# fedora or centos
$ yum install nload -y
# ubuntu/debian
$ sudo apt-get install nload
2. iftop
Iftop measures
the data flowing through individual socket connections, and it works in a
manner that is different from Nload. Iftop uses the pcap library to
capture the packets moving in and out of the network adapter, and then
sums up the size and count to find the total bandwidth under use.
Although
iftop reports the bandwidth used by individual connections, it cannot
report the process name/id involved in the particular socket connection.
But being based on the pcap library, iftop is able to filter the
traffic and report bandwidth usage over selected host connections as
specified by the filter.
$ sudo iftop -n
The n option prevents iftop from resolving ip addresses to hostname, which causes additional network traffic of its own.
Install iftop - Ubuntu/Debian/Fedora users get it from default repos. CentOS users get it from Epel.
# fedora or centos
yum install iftop -y
# ubuntu or debian
$ sudo apt-get install iftop
3. iptraf
Iptraf is an
interactive and colorful IP Lan monitor. It shows individual connections
and the amount of data flowing between the hosts. Here is a screenshot
$ sudo iptraf
Install iptraf
# Centos (base repo)
$ yum install iptraf
# fedora or centos (with epel)
$ yum install iptraf-ng -y
# ubuntu or debian
$ sudo apt-get install iptraf iptraf-ng
4. nethogs
Nethogs
is a small 'net top' tool that shows the bandwidth used by individual
processes and sorts the list putting the most intensive processes on
top. In the event of a sudden bandwidth spike, quickly open nethogs and
find the process responsible. Nethogs reports the PID, user and the path
of the program.
$ sudo nethogs
Install Nethogs - Ubuntu, Debian, Fedora users get from default repos. CentOS users need Epel
# ubuntu or debian (default repos)
$ sudo apt-get install nethogs
# fedora or centos (from epel)
$ sudo yum install nethogs -y
5. bmon
Bmon (Bandwidth
Monitor) is a tool similar to nload that shows the traffic load over all
the network interfaces on the system. The output also consists of a
graph and a section with packet level details.
Install
Bmon - Ubuntu, Debian and Fedora users can install from default repos.
CentOS users need to setup repoforge, since its not available in Epel.
# ubuntu or debian
$ sudo apt-get install bmon
# fedora or centos (from repoforge)
$ sudo yum install bmon
Bmon supports many options and is capable of producing reports in html format. Check the man page for more information
6. slurm
Slurm
is 'yet' another network load monitor that shows device statistics
along with an ascii graph. It supports 3 different styles of graphs each
of which can be activated using the c, s and l keys. Simple in
features, slurm does not display any further details about the network
load.
$ slurm -s -i eth0
Install slurm
# debian or ubuntu
$ sudo apt-get install slurm
# fedora or centos
$ sudo yum install slurm -y
7. tcptrack
Tcptrack is
similar to iftop, and uses the pcap library to capture packets and
calculate various statistics like the bandwidth used in each connection.
It also supports the standard pcap filters that can be used to monitor
specific connections.
Install
tcptrack - Ubuntu, Debian and Fedora have it in default repos. CentOS
users need to get it from RepoForge as it is not available in Epel
either.
# ubuntu, debian
$ sudo apt-get install tcptrack
# fedora, centos (from repoforge repository)
$ sudo yum install tcptrack
8. Vnstat
Vnstat is bit
different from most of the other tools. It actually runs a background
service/daemon and keeps recording the size of data transfer all the
time. Next it can be used to generate a report of the history of network
usage.
$ service vnstat status
* vnStat daemon is running
Running vnstat without any options
would simply show the total amount of data transfer that took place
since the date the daemon is running.
$ vnstat
Database updated: Mon Mar 17 15:26:59 2014
eth0 since 06/12/13
rx: 135.14 GiB tx: 35.76 GiB total: 170.90 GiB
monthly
rx | tx | total | avg. rate
------------------------+-------------+-------------+---------------
Feb '14 8.19 GiB | 2.08 GiB | 10.27 GiB | 35.60 kbit/s
Mar '14 4.98 GiB | 1.52 GiB | 6.50 GiB | 37.93 kbit/s
------------------------+-------------+-------------+---------------
estimated 9.28 GiB | 2.83 GiB | 12.11 GiB |
daily
rx | tx | total | avg. rate
------------------------+-------------+-------------+---------------
yesterday 236.11 MiB | 98.61 MiB | 334.72 MiB | 31.74 kbit/s
today 128.55 MiB | 41.00 MiB | 169.56 MiB | 24.97 kbit/s
------------------------+-------------+-------------+---------------
estimated 199 MiB | 63 MiB | 262 MiB |
To
monitor the bandwidth usage in realtime, use the '-l' option (live
mode). It would then show the total bandwidth used by incoming and
outgoing data, but in a very precise manner without any internal details
about host connections or processes.
$ vnstat -l -i eth0
Monitoring eth0... (press CTRL-C to stop)
rx: 12 kbit/s 10 p/s tx: 12 kbit/s 11 p/s
Vnstat
is more like a tool to get historic reports of how much bandwidth is
used everyday or over the past month. It is not strictly a tool for
monitoring the network in real time.
Vnstat supports many options, details about which can be found in the man page.
Install vnstat
# ubuntu or debian
$ sudo apt-get install vnstat
# fedora or centos (from epel)
$ sudo yum install vnstat
9. bwm-ng
Bwm-ng (Bandwidth
Monitor Next Generation) is another very simple real time network load
monitor that reports a summary of the speed at which data is being
transferred in and out of all available network interfaces on the
system.
$ bwm-ng
bwm-ng v0.6 (probing every 0.500s), press 'h' for help
input: /proc/net/dev type: rate
/ iface Rx Tx T
ot==========================================================================
== eth0: 0.53 KB/s 1.31 KB/s 1.84
KB lo: 0.00 KB/s 0.00 KB/s 0.00
KB--------------------------------------------------------------------------
-- total: 0.53 KB/s 1.31 KB/s 1.84
KB/s
If the console size is sufficiently large, bwm-ng can also draw bar graphs for the traffic using the curses2 output mode.
$ bwm-ng -o curses2
Install Bwm-NG - On CentOS bwm-ng can be installed from Epel.
# ubuntu or debian
$ sudo apt-get install bwm-ng
# fedora or centos (from epel)
$ sudo apt-get install bwm-ng
10. cbm - Color Bandwidth Meter
A
tiny little simple bandwidth monitor that displays the traffic volume
through network interfaces. No further options, just the traffic stats
are display and updated in realtime.
$ sudo apt-get install cbm
11. speedometer
Another
small and simple tool that just draws out good looking graphs of
incoming and outgoing traffic through a given interface.
$ speedometer -r eth0 -t eth0
Install speedometer
# ubuntu or debian users
$ sudo apt-get install speedometer
12. Pktstat
Pktstat
displays all the active connections in real time, and the speed at
which data is being transferred through them. It also displays the type
of the connection, i.e. tcp or udp and also details about http requests
if involved.
$ sudo pktstat -i eth0 -nt
$ sudo apt-get install pktstat
13. Netwatch
Netwatch
is part of the netdiag collection of tools, and it too displays the
connections between local host and other remote hosts, and the speed at
which data is transferring on each connection.
$ sudo netwatch -e eth0 -nt
$ sudo apt-get install netdiag
14. Trafshow
Like
netwatch and pktstat, trafshow reports the current active connections,
their protocol and the data transfer speed on each connection. It can
filter out connections using pcap type filters.
Monitor only tcp connections
$ sudo trafshow -i eth0 tcp
$ sudo apt-get install netdiag
15. Netload
The
netload command just displays a small report on the current traffic
load, and the total number of bytes transferred since the program start.
No more features are there. Its part of the netdiag.
$ netload eth0
$ sudo apt-get install netdiag
16. ifstat
The
ifstat reports the network bandwidth in a batch style mode. The output
is in a format that is easy to log and parse using other programs or
utilities.
$ ifstat -t -i eth0 0.5
Time eth0
HH:MM:SS KB/s in KB/s out
09:59:21 2.62 2.80
09:59:22 2.10 1.78
09:59:22 2.67 1.84
09:59:23 2.06 1.98
09:59:23 1.73 1.79
Install ifstat - Ubuntu, Debian
and Fedora users have it in the default repos. CentOS users need to get
it from Repoforge, since its not there in Epel.
# ubuntu, debian
$ sudo apt-get install ifstat
# fedora, centos (Repoforge)
$ sudo yum install ifstat
17. dstat
Dstat is a
versatile tool (written in python) that can monitor different system
statistics and report them in a batch style mode or log the data to a
csv or similar file. This example shows how to use dstat to report
network bandwidth
$ dstat -nt
-net/total- ----system----
recv send| time
0 0 |23-03 10:27:13
1738B 1810B|23-03 10:27:14
2937B 2610B|23-03 10:27:15
2319B 2232B|23-03 10:27:16
2738B 2508B|23-03 10:27:17
Install dstat
$ sudo apt-get install dstat
18. collectl
Collectl
reports system statistics in a style that is similar to dstat, and like
dstat it is gathers statistics about various different system resources
like cpu, memory, network etc. Over here is a simple example of how to
use it to report network usage/bandwidth.
$ collectl -sn -oT -i0.5
waiting for 0.5 second sample...
# <----------Network---------->
#Time KBIn PktIn KBOut PktOut
10:32:01 40 58 43 66
10:32:01 27 58 3 32
10:32:02 3 28 9 44
10:32:02 5 42 96 96
10:32:03 5 48 3 28
Install Collectl
# Ubuntu/Debian users
$ sudo apt-get install collectl
#Fedora
$ sudo yum install collectl
