ROUTER:
A device that forwards data packets along network.

Data packet:
Unit of data made into single packet and used for travels through network.

Cmd for to know IP address:
Type the IP address in browser and enter username and password.


Set up the username and password:
Wireless -> Primary -> Change network name, Pre-shared key.


DHCP Server:
Dynamic host configuration protocol.
Allots IP address to computers.
Comes as client and server.

Requirements for DHCP connection:
Need at least one DHCP server  usually it is built in router.
DHCP client is called individual computer.

Working of DHCP:
DHCP discover means the individual computer searches for DHCP server.
DHCP offer means the server offers the IP address to the computer.
DHCP Request means the host sends request to server that i have received.
DHCP Acknowledgement means the server sends IP address, subnet mask, Default gateway and DNS server.

Subnet masking:
Performs logical AND operation between IP address and Mask to produce Network address.

Default gateway:
If computer requesting web page the request first runs through default gateway before existing the local network to reach the internet.
 
How to set up a lease time:
Start -> programs -> Administrative tools -> DHCP server.
Expand the server.
Right click the scope whose lease time you want to change and select properties.
Select general tab.
At bottom you can select lease time.