1) Ifconfig is used to configure the kernel-resident network interfaces.


2)Iwconfig is similar to ifconfig(8), but is dedicated to the wireless interfaces. It is used to set the parameters of the network interfacewhich are specific to the wireless operation (for example : the frequency). Iwconfig may also be used to display those parameters, and the wireless statistics (extracted from /proc/net/wireless).


3)traceroute tracks the route packets taken from an IP network on their way to a given host. It utilizes the IP protocol's time to live (TTL)field and attempts to elicit an ICMP TIME_EXCEEDED response from each gateway along the path to the host.


4)ping uses the ICMP protocol's mandatory ECHO_REQUEST datagram to elicit an ICMP ECHO_RESPONSE from a host or gateway. ECHO_REQUEST
datagrams (“pings”) have an IP and ICMP header, followed by a struct timeval and then an arbitrary number of “pad” bytes used to fill out the packet.
ping works with both IPv4 and IPv6. Using only one of them explicitly can be enforced by specifying -4 or -6.
ping can also send IPv6 Node Information Queries (RFC4620). Intermediate hops may not be allowed, because IPv6 source routing was deprecated (RFC5095).


5)Route manipulates the kernel's IP routing tables. Its primary use is to set up static routes to specific hosts or networks via an inter‐face after it has been configured with the ifconfig(8) program.When the add or del options are used, route modifies the routing tables. Without these options, route displays the current contents of the routing tables.


File /etc/resolve:
The /etc/resolv.conf is resolver configuration file for Linux and UNIX like operating systems.
It is used to configure dns name servers.

The file /etc/resolv.conf file contains information that is read by the resolver routines the first time they are invoked by a process.
The file is designed to be human readable and contains a list of keywords with values that provide various types of resolver information.
You need to update this file with your own caching dns server or ISPs caching dns server that you want to use the resolver should query.
You can view this file with cat command itself:

cat /etc/resolv.conf
https://bash.cyberciti.biz/guide//etc/resolv.conf




Sound Ncs Channel https://www.youtube.com/watch?v=pZzSq8WfsKo
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https://www.youtube.com/watch?v=sVsyZwfKu20