Quiz Entry - updated: 2026.07.14
What are the three methods for IPv4 and IPv6 coexistence during the transition?
Dual stack (run both protocols at once), tunneling (encapsulate IPv6 inside IPv4), and translation/NAT64 (convert between IPv4 and IPv6).
IPv4/IPv6 Coexistence Methods:
| Method | Description |
|---|---|
| Dual Stack | Devices run BOTH IPv4 and IPv6 simultaneously |
| Tunneling | IPv6 packets encapsulated inside IPv4 packets |
| Translation (NAT64) | Translates between IPv4 and IPv6 packets |
Dual Stack:
- Preferred method during transition
- Device has both IPv4 and IPv6 addresses
- Uses IPv6 when available, falls back to IPv4
- Most modern OS support dual stack
Tunneling:
- Carries IPv6 packets across IPv4-only infrastructure
- IPv6 packet becomes payload of IPv4 packet
- Common protocols: 6to4, ISATAP, GRE tunnels
Translation (NAT64):
- Allows IPv6-only devices to communicate with IPv4-only devices
- Similar to IPv4 NAT
- Useful when endpoints can't be dual-stacked
Go deeper:
IPv6 transition mechanism (Wikipedia) — catalogues dual-stack, the tunnelling families (6to4, 6rd, ISATAP, Teredo) and NAT64/DNS64 translation.