Nguyễn Khánk's Wiki

# Obtaining IP / ARP / DHCP

# IP Address assignment

  • MAC Address (6 bytes) : data link layer (L3)
    • first 3 bytes: Organizational Unique Identifier
    • last 3 bytes: Vendor Assigned (NIC Cards, Interfaces)
  • IP Network (4 bytes): network layer (L2)

Mac address vs IP address

# Static addressing

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# Dynamic addressing - DHCP

DHCP = Dynamic Host Configuration Protocol

defined range of IP addresses (scope) on A DHCP server

# Process

process

  • Client Request : DHPC Discover / UDP Broadcast
  • Server Response : DHPC Offer / UDP Broadcast
    • IP Address
    • Lease time
    • DHCP Server IP
    • Address
  • Client Request : DHPC Request
  • Server Response : DHPC Ack
    • Gateway
    • Ip of other servers
    • ...

# Address Resolution Protocol (ARP)

How ARP works?

  • ARP enables a computer to find the MAC address of the computer that is associated with an IP address
  • In order for devices to communicate, the sending devices need both IP addresses & the MAC addresses of the destination devices.
  • When they try to communicate with devices whose IP addreses they know, they must determine the MAC addresses
  • ARP table stores in RAM

ARP

Destination local

Find Device or IP Address using MAC Address (opens new window)

← Ethernet →