Protocol/Proto-col/ports/Ports And Protocols/Internet protocol
Ports And Protocols:
#Chapter Outline:
1. What are ports and protocols2. Important ports and protocols
3. Primary Network Types
4. Important Networking Terms :
a. PID
b. MAC Address
C. IP Address
d. NETBIOS Name
5. Other Important Protocols :
a. Address Resolution Protocol
b. Dynamic Host Configuration Protocol
C. Internet Control Message Protocol
d. File Transfer Protocol
e. Simple Mail Transfer Protocol
6. Practical Included:
a. Viewing ARP Tables
b. Viewing all TCP/UDP Connection and Listening Ports using Netstat.
#Ports:
A port is a logical access channel between two devices which helps in their communication. A port is used to transfer the data. There are a total of 65535 ports.1. Well Known Ports : 0 to 1023
2. Registered Ports: 1024 to 49151
3. Dynamic/Private Ports: 49152 to 65535
#Some of the useful ports are:
| Ssh | 22/tcp |
| telnet | 23/tcp |
| Stmp | 25/tcp |
| http | 80/tcp |
| kerberos | 88/tcp |
| Pop3 | 110/tcp |
| imap | 143/tcp |
| htpps | 443/tcp |
| Ftps-data | 989/tcp |
| Ftps | 990/tcp |
| telnets | 992/tcp |
| imaps | 993/tcp |
| Pop3s | 995/tcp |
| LDAP | 389/tcp |
#Protocol:
The protocol is simply a set of rules which defines a standard way of exchanging information over a network.#Most commonly used protocol is:
1. Transmission Control Protocol (TCP):
TCP is one of the core parts of IPS (internet protocol suite). Another component is the IP. TCP stands for Transmission control protocol. TCP provides the facility to exchange information or data directly between two hosts. Many major internet applications like e-mail, file transfer, etc. rely upon TCP. This protocol contains a variety of flags like SYN, ACK, RST, FIN, etc.2. Internet Protocol (IP):
Internet Protocol is another core part of IPS. IP is the main communication protocol which is used for exchanging packets over inter-network using IPS. IP is used to deliver packets from source to destination.Internet protocol is responsible for the establishment of the internet.
3. User Datagram Protocol (UDP):
The user datagram protocol (UDP) does not contain any flag. UDP allows computer applications to send messages over internet protocol (IP). In UDP, data or messages are considered as DATAGRAM. UDP was designed by David P. Reed in 1980. In UDP, a simple transmission model is used and there is no hand-shaking method is used which results in unreliability, duplication, and missing of the information without notice. Data on the internet is generally organized into standard TCP or UDP packets. A packet is a bunch of information. Different services use different ports to exchange information.#Primary Network Types:
1. Local Area Network (LAN);
In LAN, a computer network covers small local area home, office, and small workgroups such as schools university. Wi-Fi and Ethernet are commonly used for LAN U2. Wide Area Network (WAN)
In WAN, a computer network cover larger a national or regional level. A wide area network can be used as a Local area network, metropolitan area network (MAN), or for campus area network(CAN).3.Wireless Local Area Network:
In WLAN, devices are connected wirelessly by the mechanism of the wireless distribution method (OFDM Radio or any other). In WLAN, generally an access point provides the connectionand hence provides the user an ease of mobility. WLAN is easy to install and maintain. However it became very popular these days with laptops and Personal Devices.
It had observed that at railway stations, malls, hotels, etc. are equipped with WLAN.
#Important Terms Associated with Network:
1. PID:
PID stands for a Product Identification number. PID is used to provide identification to a standalone system on a network. Pid was developed to solve the problem of identification. In this, a unique id was hardcoded on the NIC (Network interface card). But due to the production of NIC by more than one Manufacturer, conflicts were seen. Hence PID was not much efficiently used for identification.2. MAC Address:
Mac Address stands for Media Access Control Address. MAC address is 48 bits hexadecimal number which is a unique number assigned to the network adaptors or NIC. Mac address is the combination of PID and CID (Company Identification Number). the mac address is also known as the physical address.For Ex : AE:20:62:B4:A8:76 3. IP Address
IP Address stands for internet protocol address. The IP address is used for addressing the network so that it can be detected and used for transferring the information or messages. Ip address is 32 bits. The value of the IP address is in numeric format.
Forex : 127.0.0.1 (IPv4)
# Ip address can be assigned by two methods:
1. Static Ip:
Static IP is a fixed IP of a system that doesn't changeautomatically.
2. Dynamic Ip:
Dynamic IP is IP assigned to a system that gets changedwhen the system or connection is restarted.
3. NetBios Name:
Netbios name is the identifier of the IP address. For example the NetBIOS name of XYZ represents its IP address. Net Bios names are 16 characters long and may consist of alpha-numeric values.# Other Important Protocols
1. Address Resolution Protocol (ARP):
ARP is present in the Network layer (layer 3) of the OSI model. It is used to resolve IP address into the mac address.Viewing ARP Tables:
1. Open Command Prompt.
2. Type “arp -a".
3. ARP tables will be shown up (Shown in the screenshot)
2. Dynamic Host Configuration Protocol (DHCP):
DHCP lets the server automatically assign an IP address to the user system from a provided range of IP addresses. The DHCP server is available for windows as well as Unix based operating systems. Many of the routers come with DHCPpre-configured.
3. Internet Control message protocol (ICMP):
ICMP is used for sending the error messages indicating the host is unreachable or requested service is not available. ICMP rely upon IP to perform its tasks. Unlike TCP and UDP, it is not used for exchanging the information between two hosts. Generally, it is not used by the user network application.4. File Transfer Protocol (FTP) :
File transfer protocol is a standard protocol used for transferring the files from one host to another over the TCP/IP based network connection.FTP is either used with an authentication password or with anonymous access. FTP runs on Port 21.5. Simple Mail Transfer Protocol (SMTP):
SMTP is the standard protocol used for exchanging electronic mail (e-mail) across the IP networks. SMTP Uses port 25 on TCP(for outgoing mail transfer).#Viewing all TCP/UDP Connection and Listening Ports using Netstat:
1. Open Command prompt.
2. Type "netstat -an” (for the purposes mentioned above,
shown in screenshot).
3. To explore more about netstat command type "netstat -h” or "netstat /?” to open the help window.
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Ports And Protocols