1.1 Explain the purposes and uses of ports and protocols
Lightweight Directory Access Protocol over TLS/SSL (LDAPS)
* An application protocol for accessing and maintaining directory information services throughout a network. * Uses SSL or TLS to secure the process and provide a means for the server to authenticate to the client, providing mutual authentication. * It's based on a client-server model and runs on a layer above the TCP/IP stack, known as the Session Layer.
Enhanced Interior Gateway Routing Protocol (EIGRP)
A Cisco proprietary hybrid protocol that uses "hello" packets broadcasted every 60 seconds to form neighbor relationships, has metrics of bandwidth, delay, load, reliability and MTU, is classless (uses VLSM), can support different protocols with PDMs and implements DUAL as it's algorithm to choose best paths to networks. It has elements of both distance vector and link state routing.
Simple Network Management Protocol (SNMP)
A TCP/IP protocol that exchanges management information between networked devices. It allows network administrators to remotely monitor, manage, and configure devices on the network.
Internet Control Message Protocol (ICMP)
A TCP/IP protocol that is used by devices to communicate updates or error information to other devices. It's used in tool like Ping and Traceroute.
Secure Shell (SSH)
A UNIX-based command interface and protocol for securely accessing a remote computer.
H.323
A VoIP standard that handles the initiation, setup, and delivery of VoIP sessions. It preceded the Session Initiation Protocol, which is widely in use today.
Port 22
Secure Shell (SSH) & Secure File Transfer Protocol (SFTP)
Telnet
Port 23
Layer 6 of the OSI Model
Presentation layer. Encoding/Encryption (Ex: SSL/TLS)
Remote Desktop Protocol (RDP)
Provides a GUI for remote administration, sending screen, audio, and keyboard/mouse input data from a remote host to the client.
Transmission Control Protocol (TCP)
Provides connection-oriented data management and reliable data transfer
Stratum 2 device
Pulls its time from a stratum 1 device; so a device that queries an NTP server is stratum 2
Port 3389
RDP (Remote Desktop Protocol)
Port 5004/5005
Real Time Protocol (RTP), which enables programs to manage "real-time" transmission of multimedia data.
Layer 1 of the OSI Model
Physical layer. Signaling, Cabling, Connectors. (Ex: Cable, Network Interface Card, Hub)
Quality of Service (QoS)
Policies that control how much bandwidth a protocol, PC, user, VLAN, or IP address may use.
Port Mirroring/Spanning
Used to send the exact same packets out of multiple interfaces on a switch.
IEEE 802.1X
A standard that defines a Port-based Network Access Control (PNAC) mechanism. PNAC means that the switch (or router) performs some sort of authentication of the attached device before activating the port.
Management Information Base (MIB)
A virtual database included in an SNMP-compliant device, containing information about configuration and state of the device that can be queried by the SNMP management station.
Domain Name Server
A computer that attempts to translate a hostname into an IP address
Border Gateway Protocol (BGP)
A core routing protocol that bases routing decisions on the network path and rules.
Lightweight Directory Access Protocol (LDAP)
A directory service protocol that defines how a client can access information, perform operations, and share directory data on a directory server.
Trivial File Transfer Protocol (TFTP)
A light version of FTP that uses a small amount of memory and has limited functionality. It does not guarantee delivery and is only recommended for the transfer of small files.
Common Internet File System (CIFS)
A method for accessing data in Windows networks. CIFS is a public version of Server Message Block (SMB) that was invented by Microsoft.
Post Office Protocol version 3 (POP3)
A protocol for retrieving e-mail messages from an e-mail server. Cannot sync multiple devices. Removes mail from the mail server once downloaded.
Remote Authentication Dial-In User Service (RADIUS)
A protocol that enables a server to provide standardized, centralized authentication for remote users.
Server Message Block (SMB)
A protocol used by Windows to share files and printers on a network. One version of SMB is the Common Internet File System (CIFS)
Internet Message Access Protocol (IMAP)
A protocol used to retrieve email messages. IMAP is similar to POP3, but with some advanced features. The main difference between the two is that IMAP generally leaves the email on the mail server.
Secure File Transfer Protocol (SFTP)
A secure version of a file transfer protocol that utilizes SSH and runs on port 22.
Stratum 1 device
A server that directly cables to a stratum 0 device, like an atomic clock, to receive precise timing.
Simple Mail Transfer Protocol (SMTP)
An Internet-standard protocol for sending email messages between servers on IP networks. Users typically use a program that uses SMTP for sending e-mail, and either POP3 or IMAP for receiving e-mail.
Point-to-Point Tunneling Protocol (PPTP)
An enhanced version of PPP, which adds the ability to secure the point-to-point connection with encryption.
Open Shortest Path First (OSPF)
An interior gateway routing protocol developed for IP networks based on the shortest path first or link-state algorithm.
Layer 7 of the OSI Model
Application layer. Layer We See (Ex: Gmail, Twitter, Facebook)
Port 20/21
File Transfer Protocol (FTP) uses ports 20 and 21. Port 20 is used for data and port 21 is used for control. As the name implies, FTP is used for file transfer, though not secure.
Port 67 & 68
DHCP
Port 53
DNS (Domain Name System)
Layer 2 of the OSI Model
Data Link layer. The Switching Layer (Ex: Frame, MAC Address, EUI-48, EUI-64, Switch)
Spanning Tree Protocol (STP)
Defined by the IEEE 802.1D standard, it allows a network to have redundant Layer 2 connections, while logically preventing a loop, which could lead to symptoms such as broadcast storms and MAC address table corruption.
Dynamic Host Configuration Protocol (DHCP)
Dynamically assigns IP address information (for example, IP address, subnet mask, DNS server's IP address, and default gateway's IP address) to network devices.
Port 443
HyperText Transfer Protocol over SSL (HTTPS) traffic, which is secure web traffic.
Port 143
Internet Mail Access protocol (IMAP), which plays a part in electronic mail transfers.
Port 123
Network Timing Protocol (NTP), which provides precise timing to network devices.
Layer 3 of the OSI Model
Network layer. The Routing Layer (Ex: IP Address, Router, Packet)
Session Initiation Protocol (SIP)
One of the most widely-used session control protocols in VoIP communications. As the name implies, it is the protocol that initiates the session to connect users on a call.
Address Resolution Protocol (ARP)
Part of the TCP/IP protocol for determining the MAC address based on the IP address.
Layer 5 of the OSI Model
Session layer. Communication between devices (Ex: Control Protocols, Tunneling Protocols)
Port 25
Simple Mail Transfer Protocol (SMTP)
Port 161/162
Simple Network Management Protocol (SNMP), which is used for managing network devices.
Simple Network Time Protocol (SNTP)
Simple Network Time Protocol (SNTP) is a simplified version of Network Time Protocol (NTP) that is used to synchronize computer clocks on a network. This simplified version of NTP is generally used when full implementation of NTP is not needed.
Private Branch Exchange (PBX)
Technology that manages all the office phone lines, voice mail, internal billing, call transfers, forwarding, conferencing, and other voice services. (Not IP based)
Port 23
Telnet
Internet Protocol (IP)
The network protocol that deals with the routing of packets through interconnected networks to the final destination
Hyper Text Transfer Protocol (HTTP)
The way data is transferred to an external site through a server.
Stratum 0 device
Time Reference Server, on an Atomic Clock. Requires a Stratum 1 device to distribute it's data.
Layer 4 of the OSI Model
Transport layer. The "Post Office" Layer (Ex: TCP Segment, UDP Datagram)
File Transfer Protocol (FTP)
a simple network protocol that allows the transfer of files between two computers on the internet