HTTP and HTTPS

HTTP:

HTTP is associate degree client-server protocol that enables clients to request web content from network servers. it's associate degree application level protocol widely used on the net. shoppers area unit sometimes net browsers. once a user desires to access an online page, a browser sends associate degree communications protocol Request message to the network server. The server responds with the requested web content. net servers sometimes use protocol port eighty.

Clients and net servers use request-response methodology to speak with one another, with shoppers causing the communications protocol Requests and servers responding with the communications protocol Responses. clients sometimes send their requests victimization GET or POST ways, maybe GET /homepage.html. net servers respond with a standing message (200 if the request was successful) and send the requested resource.

HTTPS:

Hypertext Transfer Protocol Secure could be a secure version of the protocol. This protocol permits secure communication between a shopper (e.g. internet browser) and a server (e.g. internet server) by victimization encoding. HTTPS uses SSL (Secure Socets Layer) protocol and for encoding and TCP port 443 for communication.

HTTPS is usually accustomed produce a secure channel over some insecure network, e.g. Internet. By default, most traffic on the web is unencrypted and prone to sniffing attacks. HTTPS encrypts sensitive data, that makes an association secure.

HTTPS is typically not used on the complete web site as a result of encoding slows down the location. Instead, it's used solely to safeguard sensitive data like usernames and passwords.

HTTPS URLs begin with protocols rather than HTTP. In web someone, you'll straightaway acknowledge that an internet website is victimization HTTPS as a result of a lock seems to the proper of the address bar.

SNMP (Simple Network Management Protocol) details

Simple Network Management Protocol (SNMP) is AN application layer protocol that's used for network device management. This protocol will collects and manipulate valuable network data from switches, routers, servers, printers, and alternative network-attached devices.

An SNMP-managed network consists of 2 components:
 

1.     Network management station (NMS) – the software system that runs on the executive pc. This software system gathers SNMP information by requiring the devices on the network to disclose sure data. Devices may inform the NMS regarding issues they're experiencing by causation AN SNMP 

2.    Agent – the software system that runs on managed devices and reports data via SNMP to the NMS.

How SNMP works?

The router R1 is organized to send SNMP traps to the NMS Station. If a retardant happens, the router can send AN SNMP lure to Host A. to Illustrate, if there's a port security violation on R1, the router can send the SNMP lure, notifying that there has been a possible security breach on the network.

NOTE – SNMP agents use a UDP port 161, whereas the manager uses a UDP port 162. this SNMP version is SNMPv3. The previous versions, SNMPv1 and SNMPv2 ar thought-about obsolete and will not be used.

What is FTP & TFTP ?

FTP (File Transfer Protocol)

FTP may be a network protocol wont to transfer files from one pc to a different over a transmission control protocol network. Like Telnet, it uses a client-network arhitecture, which implies that a user has got to have associate degree FTP shopper put in to access associate degree FTP server running on the remote machine. when establishing associate degree FTP association, the user will transfer or transfer files to and from the FTP server.

FTP uses 2 TCP ports: port twenty for causation knowledge and port twenty one for causation control commands.

FTP will use authentication, however like Telnet, all knowledge is shipped in clear text, as well as usernames and passwords.

TFTP (Trivial File Protocol)

TFTP may be a network protocol wont to transfer files between remote machines. it's an easy version of FTP, lacking a number of the additional advanced options FTP offers, however requiring less resources than FTP.

Because of it’s simplicity TFTP are often used solely to send and receive files. It uses UDP port sixty nine for communication.

Because of it’s disadvantages TFTP isn't wide used these days, however it’s wont to save associate degreed restore a router configuration or to backup an IOS image.

TFTP doesn’t support user authentication and sends all knowledge in clear text.

Telnet and SSH

What is telnet?

Telnet could be a network protocol that enables a user to communicate with a distant device. it's a virtual terminal protocol used principally by network administrators to remotely access and manage devices. an administrator will access the device by “telnetting” to the IP address or hostname of a distant device.

To use telnet, you want to have a code (Telnet client) put in. On a distant device, a Telnet server should be installed and running. Telnet uses TCP port twenty-three.

One of the main disadvantages of this protocol is that all data i.e usernames and passwords, is sent in clear text and that could be a potential security risk. This is often the most reason why Telnet isn't used nowadays and is being replaced by a far secure protocol known as SSH.

The word “telnet” can even confer with the software that implements the telnet protocol.
On Windows, you'll be able to begin a Telnet session by writing the telnet IP_ADDRESS or HOSTNAME command:

telnte-ccna-tutorials

What is SSH?

The SSH protocol (also referred to as Secure Shell) is a technique for secure remote login from one pc to a different. It provides many different choices for robust authentication, and it protects the communications security and integrity with robust cryptography.

SSH-CCNA-TUTORIALS

What is DHCP? How it works?

What is DHCP?

Dynamic Host Configuration Protocol (DHCP) is a protocol. It helps a server machine to automatically assign an IP address to a Device from a defined range of numbers configured for a given network.

Usually when we connect wifi network to our mobile/laptop then wifi router connect it and provide an IP Address automatically. Do you think which protocol is used for this? In this case basically, DHCP protocol is used. (Some Exceptional case wifi router also use static IP Address also).
 

How DHCP Work?

Here is how the DHCP process works when you go online:

1)    Your go on your computer to connect to the Internet.

2)    The network requests an IP address (this is actually referred to as a DHCP discover message).

3)    On behalf of your computer's request, the DHCP server allocates (leases) to your computer an IP address. This is referred to as the DHCP offer message.

4)    Your computer (if you're the DHCP client) takes the first IP address offer that comes along. Then it responds with a DHCP request message who verifies the IP address that's been offered and obtained.

5)    DHCP then updates the appropriate network servers with the IP address and other configuration information for your computer.

6)    Your computer (or whatever network device you're using) accepts the IP address for the lease term.

What is ARP(Address Resolution Protocol)?

What is ARP(Address Resolution Protocol)?

 

Address Resolution Protocol (ARP) is a low-level network protocol for translating network layer addresses into link layer addresses.

ARP lies between layers 2 and 3 of the OSI model, although ARP was not included in the OSI framework and allows computers to introduce each other across a network prior to communication.

Because protocols are basic network communication units, address resolution is dependent on protocols such as ARP, which is the only reliable method of handling required tasks.

ARP-CCNA-TUTORIALS

UDP

UDP

One of the important protocols in the TCP/IP site is User Datagram Protocol (UDP). UDP is basically a scaled-down version of TCP. Just like TCP, this protocol provides delivery of data between applications running on hosts on a TCP/IP network, unlike TCP, it does not sequence the data and does not care about the order in which the segments arrive at the destination. Because of this it is considered to be an unreliable protocol. UDP is also considered to be a connection-less protocol, since no virtual circuit is established between two endpoints before the data transfer takes place.

UDP application

Here are few applications where UDP is used to transmit data:

Domain Name Services

Simple Network Management Protocol

Trivial File Transfer Protocol

Routing Information Protocol

Kerberos