1. Domain Name System (DNS)
DNS translates domain names (e.g., www.example.com) into IP addresses (e.g., 192.0.2.1) and vice versa. It enables users to access websites and other resources using easy-to-remember domain names instead of numeric IP addresses. DNS operates on a hierarchical distributed database system and uses UDP port 53 for communication.
2. Dynamic Host Configuration Protocol (DHCP)
DHCP automatically assigns IP addresses and network configuration parameters (subnet mask, default gateway, DNS servers) to devices on a network. It simplifies network administration by centrally managing and allocating IP addresses dynamically to devices when they connect to the network. DHCP operates over UDP ports 67 and 68.
3. File Transfer Protocol (FTP)
FTP allows users to transfer files between a client and a server over a network. It supports uploading, downloading, and managing files on remote servers. FTP operates on TCP ports 20 (data) and 21 (control), with Secure FTP (SFTP) using SSH for encrypted file transfer.
4. Simple Mail Transfer Protocol (SMTP)
SMTP is a protocol for sending email messages between servers. It defines how email clients and servers communicate and transfer messages across the internet or internal networks. SMTP operates on TCP port 25 for communication between email servers.
5. Post Office Protocol (POP) and Internet Message Access Protocol (IMAP)
POP and IMAP are protocols used by email clients to retrieve emails from a mail server:
- POP: POP allows clients to download emails from the server to the client’s device. POP typically uses TCP port 110 (POP3) or 995 (POP3S for encrypted POP).
- IMAP: IMAP allows clients to access and manage emails directly on the server without downloading them to the client device. IMAP operates on TCP port 143 (IMAP) or 993 (IMAPS for encrypted IMAP).
6. Hypertext Transfer Protocol (HTTP) and HTTPS
HTTP is a protocol for transferring hypertext documents (web pages) between clients (web browsers) and servers (web servers). HTTPS (HTTP Secure) encrypts HTTP traffic using SSL/TLS, providing secure communication over the internet. HTTP uses TCP port 80, while HTTPS uses TCP port 443.
7. Secure Shell (SSH)
SSH provides secure, encrypted access and communication to network devices (e.g., routers, switches, servers) over an insecure network (e.g., the internet). It replaces insecure protocols like Telnet with secure command-line access and file transfer. SSH operates on TCP port 22.
8. Telnet
Telnet allows remote command-line access to network devices and servers over a TCP/IP network. It enables administrators to manage devices and configure settings remotely. Telnet transmits data in plain text, making it less secure compared to SSH. Telnet operates on TCP port 23.
9. Virtual Private Network (VPN)
VPN extends a private network across a public network (e.g., the internet) and enables users to securely access and communicate over the network as if they were directly connected to the private network. VPNs use protocols like IPsec, SSL/TLS, and PPTP (Point-to-Point Tunneling Protocol) for secure communication.
10. Network Time Protocol (NTP)
NTP synchronizes the time and clocks of computers and network devices within a network or across the internet. It ensures accurate timekeeping for operations such as logging, authentication, and transaction processing. NTP operates over UDP port 123.
11. Voice and Video Services
For the CCNP Collaboration exam, specific voice and video services are crucial:
- Session Initiation Protocol (SIP): SIP is a signaling protocol used for initiating, managing, and terminating multimedia communication sessions, such as VoIP calls and video conferencing.
- Real-Time Transport Protocol (RTP): RTP transports audio and video streams over IP networks, providing end-to-end delivery services for real-time communication.
12. Quality of Service (QoS)
QoS mechanisms prioritize network traffic to ensure optimal performance for critical services (e.g., voice and video) over less time-sensitive traffic. QoS techniques include traffic classification, prioritization, traffic shaping, and congestion management.
Understanding these network services and their protocols is essential for configuring, troubleshooting, and optimizing network infrastructure, which is critical for the mastering. Hands-on experience with collaboration technologies and network equipment will further enhance your understanding and readiness for the exam.
