Common networking protocols

Question 1

Frame Relay

Answer 1

WAN protocol that operates at the physical and data link layers of the OSI model.
For data transmission for intermittent traffic between LANs and between endpoints in a WAN. Frame Relay is a packet-switching technology

Question 2

Transmission Control Protocol (TCP)

Answer 2

A connection-oriented transport protocol.
If a segment is dropped, the sender can detect that drop and retransmit that dropped segment. sender can determine which segments were successfully received.

TCP operates at the transport layer of the OSI model.

TCP three-way handshake.

1. It sends a message called a SYN to the target host.
2. The target host opens a connection for the request and sends back an acknowledgment message called an ACK (or SYN ACK).
3. The host that originated the request sends back another acknowledgment, saying that it has received the ACK message and that the session is ready to be used to transfer data.

Question 3

UDP(User Datagram Protocol)

Answer 3

A connectionless transport protocol.

• Unreliable transport(the sender is unaware of the drop, and no retransmission occurs.)
• UDP operates at the transport layer

Question 4

File Transfer Protocol (FTP)

Answer 4

for the uploading and downloading of files from a remote host running FTP server software.
FTP is considered insecure. not encrypted.
FTP works at the transport layer of the OSI model.

Question 5

SFTP Secure File Transfer Protocol

Answer 5

A protocol that transfers files between clients securly,Based on Secure Shell (SSH) technology, provides robust authentication between sender and receiver. It also provides encryption capabilities, which means that even if packets are copied from the network, their contents remain hidden.

Question 6

TFTP Trivial File Transfer Protocol

Answer 6

A variation on FTP is TFTP,
Not secure
Associated with downloading stuff like firmware to a router.
It is connectionless(UDP)

Question 7

SMTP

Answer 7

SMTP is a protocol that defines how mail messages are sent between hosts.
SMTP uses TCP connections to guarantee error-free delivery of messages.

Question 8

HTTP(Hypertext Transfer Protocol)

Answer 8

HTTP, is the protocol that enables text, graphics, multimedia, and other material to be downloaded from an HTTP server.

Question 9

HTTPS (Hypertext Transfer Protocol Secure)

Answer 9

uses a system known as Secure Socket Layer (SSL), which encrypts the information sent between the client and host

Question 10

POP3 Post Office Protocol Version 3

Answer 10

A mechanisms for downloading, or pulling, email from a server.(Email stored at a central location)

Question 11

IMAP4 Internet Message Access Protocol V4

Answer 11

Performs the same functions as POP3; IMAP4
An advantage over POP3. It uses a more sophisticated authentication system, which makes it more difficult for people to determine a password.

Question 12

Telnet

Answer 12

Telnet is a virtual terminal protocol. It enables sessions to be opened on a remote host, and then commands can be executed on that remote host.
Telnet is commonly used to access routers and other managed network devices.
One of the problems with Telnet is that it is not secure. As a result, remote session functionality is now almost always achieved by using alternatives such as SSH.

Question 13

Secure Shell (SSH)

Answer 13

A secure alternative to Telnet. SSH provides security by encrypting data as it travels between systems. This makes it difficult for hackers using packet sniffers and other traffic-detection systems. It also provides more robust authentication systems than Telnet
2 Versions: SSH1 and SSH2. Of the two, SSH2 is considered more secure.
The two versions are incompatible

SSH is the foundational technology for Secure File Transfer Protocol (SFTP).

Question 14

(ICMP) Internet Control Message Protocol

Answer 14

error checking and reporting functionality.(works with IP)
Main Uses: PING,source quench(telling the sender to slow down. This action prevents packets from dropping and having to be re-sent.)

Question 15

Address Resolution Protocol (ARP)

Answer 15

ARP, is responsible for resolving IP addresses to Media Access Control (MAC) addresses.

When a system attempts to contact another host, IP first determines whether the other host is on the
same network by looking at the IP address.
If IP determines that the destination is on the local network, it consults the ARP cache to see whether it has a corresponding entry. The ARP cache is a table on the local system that stores mappings between data link layer addresses (the MAC address or physical address) and network layer addresses (IP addresses).

Question 16

RARP Reverse Address Resolution Protocol

Answer 16

(RARP) Performs the same function as ARP, but in reverse. In other words, it resolves MAC addresses to IP addresses. RARP makes it possible for applications or systems to learn their own IP address from a router or Domain Name Service (DNS) server. Such a resolution is useful for tasks such as performing reverse lookups in DNS

Question 17

NTP Network Time Protocol

Answer 17

NTP is the part of the TCP/IP protocol suite that facilitates the communication of time between systems.

Question 18

SCP Secure Copy Protocol

Answer 18

Secure Copy Protocol (SCP) is another protocol based on SSH technology. SCP provides a secure means to copy files between systems on a network.

Question 19

LDAP Lightweight Directory Access Protocol

Answer 19

LDAP is a protocol that provides a mechanism to access and query directory services systems.

these directory services systems are most likely to be Novell Directory Services (NDS) and Microsoft’s Active Directory.

Although LDAP supports command-line queries executed directly against the directory database, most LDAP interactions are via utilities such as an authentication program (network logon) or locating a resource in the directory through a search utility. IGMP Internet Group

Question 20

IGMP Internet Group Management Protocol

Answer 20

Grp message.

The protocol within the TCP/IP protocol suite that manages multicast groups.

It enables, for example, one computer on the Internet to target content to a specific group of computers that will receive content from the sending system.

IGMP is used to register devices into a multicast group, as well as to discover what other devices on the network are members of the same multicast group. Common applications for multicasting include groups of routers on an internetwork and videoconferencing clients.

Question 21

TLS Transport Layer Security

Answer 21

A security protocol designed to ensure privacy between communicating client/server applications. When a server and client communicate, TLS ensures that no one can eavesdrop and intercept or otherwise tamper with the data message. TLS is the successor to SSL. TLS record protocol: Uses a reliable transport protocol such as TCP and ensures that the connection made between systems is private using data encryption.
TLS handshake protocol: Used for authentication between the client and server.

Question 22

SIP Session Initiation Protocol

Answer 22

An application layer protocol designed to establish and maintain multimedia sessions, such as Internet telephony calls. This means that SIP can create communication sessions for such features as audio/videoconferencing, online gaming, and person-to-person conversations over the Internet. SIP does not operate alone; it uses TCP or UDP as a transport protocol. VOIP…

Question 23

RTP The Real-time Transport Protocol

Answer 23

Internet-standard protocol for the transport of real-time data, including audio and video.
UDP is used more often

The control part (RTCP) supports real-time conferencing of groups of any size within an internet.

Question 24

(DHCP)Dynamic Host Configuration Protocol

Answer 24

enables ranges of IP addresses for lease to hosts on a network(DHCP client ask for addresses form DHCP server) Also Subnetmask/ default gateway.
Lease:Length of time
Scope:Range of addresses
Reservation:- for specific addresses

Question 25

SNMP(Simple Network Management Protocol)

Answer 25

Provides network devices with a method to monitor and control network devices; manage configurations, statistics collection, performance, and security; and report network management information to a management console.
Both SNMPv1 and v2 are not secured. SNMPv3 An enhanced SNMP service offering both encryption and authentication services.
SNMP agent
SNMP trap

Question 26

NMS (Network Management System)

Answer 26

An application that acts as a central management point for network management. Most NMS systems use SNMP to communicate with network devices.

Question 27

SNMP Communities.

Answer 27

SNMP communities are logical groupings of systems. When a system is configured as part of a community, it communicates only with other devices that have the same community name. In addition, it accepts Get, Get Next, or Set commands only from an SNMP manager with a community name it recognizes.

Question 27

STP

Answer 27

Spamming Tree Protocol - prevent looping