Module 10 · Section 1.3.2
Addressing
MAC Address
Physical Address
- Hardcoded into the NIC by the manufacturer.
- Globally unique. Format: 6 pairs of hex digits.
- Used by switches to direct frames within a LAN.
IP Address (IPv4 vs IPv6)
Logical Address
- Assigned to the device by the network — can change.
- Used by routers to direct packets across networks.
- IPv4: 4 denary octets. Running out of addresses.
- IPv6: Uses Hexadecimal. Created because IPv4 ran out.
| Feature | MAC Address | IP Address |
|---|---|---|
| Type | Physical | Logical |
| Used by | Switch | Router |
| Changes? | Never | Yes |
⚠ Examiner Warning: IPv4 validity
Each octet in an IPv4 address must be 0–255. A value like "256" is invalid. Always check this in exam questions.
🏷 MAC Address — Physical
00:1A:2B:3C:4D:5E
6 pairs · Hexadecimal · Hardcoded
🌐 IPv4 Address — Logical
192.168.1.254
4 octets · Denary · Assigned by network
MAC = Physical · IP = Logical