Monday, November 24, 2014

Basics of Telnet and other protocols

Some useful networking protocols in brief

Telnet (Terminal Emulation):

It Allows Users from remote client system to connect or access other client system or resources, Servers. By using telnet client software one can access/log in to  the server.

SMTP (Simple Mail Transfer Protocol):

Doing the process for email delivery, message queuing , checking the message, spooling the message.

TFTP (Trivial File Transfer Protocol):

It is being used only for sending and receiving files of very small amount mean small data. It does not have directory browsing facility and it is not secure method .

FTP (FILE TRANSFER PROTOCOL):
It is the real protocol used for transfer for files. it is not just a protocol but also a programme. Most of FTP client and server software are now available to the market. It have authentication of users , allows to access the directories of files, browsing of directory, copy paste options.

It is faster than email while sending or receiving Large Files while we know some email services provide max 25 MB of data to be attached.

IMAP(Internet Message Access Protocol):

Used for making control over mails, downloading mails, Gives option for search mail with commands based on message subject, header, to mail etc. You  can store mails on mail Server. Now its being used as Version 4 and so far called IMAP4. Before IMAP there was POP ( Post Office protocol ) which was earlier used to store incoming mail but it does not allow to download mails selectively. 

SNMP(Simple Network Management protocol):

This protocol Collects & Pulls valuable network information, gathers the data of the devices connected in a network with some time intervals. This protocol also notices and alerts any events happening in a network.
version 1, 2, 3 available. v3 have more security, encryption and authenticity option.

SSH ( Secure Shell ):

It conducts a secure telnet session over a standard tcp/ip connection. And is assigned for logging in to systems, running programs on remote system, moving files from one system to another, remote command execution. Client software available freely like putty, open ssh. 
SSH CONNECTION


HTTP ( HYPERTEXT TRANSFER PROTOCOL ):

It is used to manage communications between web browser and web servers when we click on a link for any resource. It retrieves the data as per its name from different location around the world.

HTTPS ( Secure ):
 Its a Secure Protocol for HTTP and it uses secure socket layer.It enables you to do transactions online secure, whether in any log in process or for eCommerce use.

DNS:
Domain Name Service ( System ) 

It resolves Host name. DNS allows to use the domain name HOSTs to specify IP Address. It is being easy to remember than the IP Address, so it uses Alphabetic characters. Similarly the domain name converts it in to respective IP Addresses.

 After that a DNS is used to resolve a FQDN ( Fully Qualified Domain Name ).It specifies the exact location of the Domain name i.e. Host name + Domain Name. The DNS Server solves it by using the looking of DNS Table.

DHCP:
Dynamic Host Configuration Protocol
It Assigns IP Address to Hosts/clients . It allows Administration and control over a network of small or Large.

A DHCP Server provides the information as : 
  •  IP Address
  •  Subnet Mask
  •  Domain Name
  •  Default Gateway { IP Address of Router }
  •  DNS Server address
  •  WINS Server Address

Hence the DHCP conflict occurs in a network when there are Two same IP Address is given to two Hosts.
While assigning IP Address, It checks the availability of IP address by pinging request then resumes in the network.

Post Office Protocol (POP):

The POP protocol uses basically in email messaging. It provides the storage facility for all incoming mail. The used POP is called POP3.

Transport Layer Security (TLS):

The TLS protocol is one of the encryption protocol same as SSL (Secure Socket Layer) protocol. It enables secure online data transfer during browsing,  messaging, etc.

ARP

An Address Resolution Protocol (ARP) finds the hardware address of host from a known IP address. When IP has a datagram to send, it must inform a Network Access protocol, such as Ethernet or Token Ring, of the destination’s hardware address on the local network. ARP resolves IP addresses to Ethernet addresses.

-DR

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