The Internet layer matches OSI Layer . Its primary protocol is IP.
Responsibilities:
- Addressing: unique IP addresses
- Routing: forwarding across networks
- Fragmentation: splitting for smaller MTUs
Supporting protocols:
- ICMP: diagnostics (ping)
- ARP: IP to MAC mapping
IP is connectionless. Packets route independently and may arrive out of order. Layer sorts them. IPv4 uses -bit addresses. IPv6 uses bits.