Traceroute command:
Traceroute is a computer network diagnostic tool for displaying the route (path) and measuring transit delays of packets across an Internet Protocol (IP) network.

Traceroute is available almost in all operating systems. In Microsoft OS you can use tracert command.

When we apply Tracert command in MS windows then first of all it display the IP address of given domain, and what the maximum number of hops will be before it times out.

Next it gives information about each router it passes through on the way to its destination and then information of ISP the origin computer is connected.

For example:

C:\ tracert yahoo.com

Ipconfig command:
Ipconfig command displays all current TCP/IP network configuration values. When we use simple ipconfig command without any parameters then its display the IP address, subnet mask, and default gateway for all adapters. We can also use Ipconfig command with different parameters which are:

/all : Displays the full TCP/IP configuration for all adapters.

/renew [Adapter] : Renews DHCP configuration for all adapters (if an adapter is not specified) or for a specific adapter if the Adapter parameter is included. This parameter is available only on computers with adapters that are configured to obtain an IP address automatically.

/release [Adapter] : Release the current DHCP configuration and discard the IP address configuration for either all adapters or for a specific adapter.

Syntax

ipconfig [/all] [/renew [Adapter]] [/release [Adapter]] [/flushdns] [/displaydns] [/registerdns] [/showclassid Adapter] [/setclassid Adapter [ClassID]]

Ping Command:
Ping command is an external command which is used to test the network connections. When we connect any device with other device then ping command verify that a device can communicate with another on a network. The ping command basically send request messages to the destination device and waiting for a response and then display that how many of those responses are returned, and how long it takes for them to return.

Syntax

ping [- option] destination

For example Ping yahoo.com

Where Options are:

-t Pings the specified host until stopped.

-a Resolve addresses to hostnames.

-n Count Number of echo requests to send.

-w Timeout in milliseconds to wait for each reply.

For Example:

Ping -t yahoo.com

What is Router?
Router is device which connect two networks for example local network and internet. Routers determine whether the source and destination are on the same network or whether data must be transferred from one network type to another. Routers contain software called firmware for example it contains DHCP which provide IP address to all connected device. Router is also providing the facility of Switch or Hub. Router is also use as access point. For example, routers are commonly used in home networks to share a single Internet connection between multiple computers through cable or wirelessly through Wi-Fi.

What is Gateway?
Gateway is a network point that acts as an entrance to another network. When router routing the information from one network to another network then gateway specify the exits point and when any information is coming from another network then gateway is entry point. for example a device which is provide from ISP for internet service is a getaway which create exist and entry point to next network.

What is Repeaters?
Repeater is a hardware device, which is used to extend LAN. When the distance of local area network is to long then we use a special device repeater which Receive analog data and convert to digital data and the regenerate a new clean analog signal. The repeater connects directly to the cable. The maximum size of LAN is 500 meter so we can increase this size by using a pair of repeater by connecting each LAN segment to make a network, 1500 meter long.

What is Bridges?
The bridge is a hardware that connects a LAN to LAN that uses the same protocol. The function of Bridges is its filter and reduced the traffic. For example when a message is send from any computer then its decides whether a message from you to someone else is going to the local area network or other local area network.