TCPdump is a very powerful command line interface packetsniffer.

Step 1. Install TCPdump

apt-get install tcpdump

Stept 2. TCPdump use

Step 2.1 To display the Standard TCPdump output:

tcpdump
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
15:14:25.060050 IP 89.35.90.202.clax.ro.27015 > h89-37-110-61.teleson.ro.27005: UDP, length 229
15:14:25.060071 IP 89.35.90.202.clax.ro.27015 > 86-124-241-9.rdsnet.ro.27005: UDP, length 374
15:14:25.060213 IP 86-124-240-65.rdsnet.ro.27005 > 89.35.90.202.clax.ro.27015: UDP, length 78
15:14:25.060236 IP 91-213-135-21.optic-bridge.com.ro.45249 > 89.38.255.34.28822: UDP, length 20
15:14:25.060240 IP 89.35.90.202.clax.ro.27015 > 86-124-240-65.rdsnet.ro.27005: UDP, length 221
15:14:25.060481 IP 89.35.90.202.clax.ro.27015 > 78-21-42-14.access.telenet.be.27005: UDP, length 163
15:14:25.060694 IP 89.35.90.202.clax.ro.27015 > user-ip-23-89-33-89-sel.rdsnav.ro.63087: UDP, length 224
15:14:25.060731 IP 89.35.90.202.clax.ro.32783 > ns1.clax.ro.domain: 65251+ PTR? 61.110.37.89.in-addr.arpa. (43)
15:14:25.060830 IP 89.35.90.202.clax.ro.27015 > 92.83.223.46.61499: UDP, length 113
15:14:25.060851 IP 89.35.90.202.clax.ro.38331 > 89.35.90.18.clax.ro.62613: P 2328008232:2328008428(196) ack 4034406897 win 410
15:14:25.060910 IP 89.35.90.202.clax.ro.27015 > 86-121-72-43.rdsnet.ro.27005: UDP, length 109
15:14:25.060966 IP 92.83.176.255.27005 > 89.35.90.202.clax.ro.27015: UDP, length 74
15:14:25.061020 IP 89.35.90.202.clax.ro.27015 > 95-65-79-185.starnet.md.27005: UDP, length 117

Step 2.2 Network interfaces available for the capture:

Wget is a free utility for non-interactive download of files from the Web.  It supports HTTP, HTTPS, and FTP protocols, as well as retrieval through HTTP proxies.

Using Wget to download entire website:

Step 1. Create directory where you are planing to store the website content:

mkdir /home/user/offline_site

Usually, source code are compress in the archive format, its either tar.gz (.tgz) or bz2.

The command uses to extract these archive is tar. Let say your archive is test.2.tar.gz.

You can decompress it and extract to your folder like this:

tar -xzvf xyz2.29.tar.gz -C /usr/src

*-C is to indicate tar where to store the extracted files.

Common open source programs source code comes with configure files and makefiles. Because those programs usually are cross platform compatible. That means it can be compile in different platform such as Unix, Linux, BSD etc, given the required library installed and the dependencies solved. Therefore, before start to compile and install, you usually need to configure.

./configure

vnStat is a console-based network traffic monitor for Linux and BSD that keeps a log of network traffic for the selected interface(s). It uses the network interface statistics provided by the kernel as information source. This means that vnStat won’t actually be sniffing any traffic and also ensures light use of system resources.

Step 1. Installation:

apt-get install vnstat

Step 2. Select the interface you wish to monitor:

for eth0 :

vnstat -u -i eth0

Repeat this changing eth0 for each interface you wish to monitor.

NOTE: Once the text database have been initialised you’re ready to monitor your bandwidth usage. The package installs a cronjob which will update the database every five minutes.

Lm-sensors is a hardware health monitoring package for Linux. It allows you to access information from temperature, voltage, and fan speed sensors. It works with most newer systems.

Step 1.  Install lm-sensors using apt-get.

Run the following command:

apt-get install lm-sensors

Step 2. Detect your sensors using the following command:

sensors-detect