Name the layers of the TCP/IP model.

#4 layers of the TCP/IP model

The TCP/IP model consists of four layers, listed from bottom to top.

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#1. Network Access Layer

Combines OSI layers 1 and 2.

Functions:

• transmitting frames over the physical medium
• working with MAC addresses
• Ethernet, Wi-Fi, PPP

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#2. Internet Layer

Equivalent to the OSI network layer (L3).

Functions:

• IP addressing
• routing
• delivering packets between networks

Protocols:

• IPv4 / IPv6
• ICMP / ICMPv6
• ARP / NDP
• OSPF, BGP, RIP

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#3. Transport Layer

Equivalent to OSI layer 4.

Functions:

• segmentation
• delivery management
• TCP/UDP ports

Protocols:

• TCP
• UDP

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#4. Application Layer

Combines OSI layers 5, 6, and 7.

Functions:

• network services for applications
• working with upper-layer protocols

Protocols:

• HTTP/HTTPS
• DNS
• FTP/SFTP
• SMTP/IMAP/POP3
• DHCP
• SSH
• SNMP

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#Short answer for an interview

The 4 layers of TCP/IP: Network Access, Internet, Transport, Application.

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#Cheat sheet (5 seconds)

TCP/IP:

1. Network Access
2. Internet
3. Transport
4. Application