Understanding MAC, IPv4, and IPv6
MAC Address
- Burned into the Network Interface Card (NIC) by the manufacturer.
- Known as the physical address and is unique for each device.
- Also called Media Access Control (MAC) address.
- Consists of 48 bits, divided into:
- 24-bit OUI (Organizationally Unique Identifier): Vendor code, same for all devices from that vendor.
- 24-bit Device Identifier: Differentiates individual devices from the same vendor.
- Used by Layer 2 (L2) devices (like switches) for forwarding decisions.
IPv4 & IPv6 Addresses
- IPv4: 32-bit address.
- IPv6: 128-bit address.
- Used by Layer 3 (L3) devices (like routers) to forward traffic.
- Unlike MAC addresses, IP addresses are not fixed to a device and can be assigned statically or dynamically (via DHCP).
How MAC & IP Are Used in Networking
- Switches use MAC addresses to build a MAC table and determine connected devices.
- Routers use IP addresses to build a routing table and make forwarding decisions.
Stay tuned! Next post will explain how L2 & L3 traffic forwarding works.
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