# DHCPv6: Rapid Commit option received but server 2001:db8::1 returned no IA_NA addresses

- **ID:** `networking/dhcpv6-rapid-commit-failure`
- **Domain:** networking
- **Category:** protocol_error
- **Verification:** ai_generated
- **Fix Rate:** 76%

## Root Cause

A DHCPv6 client using the Rapid Commit option (two-message exchange) received a Reply from the server that lacks any IA_NA (Non-temporary Address) options, indicating the server has no addresses to assign, often due to exhausted address pools or misconfigured DHCPv6 scope.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| ISC DHCP 4.4.3 | active | — | — |
| Kea 2.4.1 | active | — | — |
| dnsmasq 2.90 | active | — | — |
| systemd-networkd 254 | active | — | — |

## Workarounds

1. **In Kea: modify 'subnet6' section to increase pool size, e.g., 'pool': '2001:db8::/64' to '2001:db8::/56'** (85% success)
   ```
   In Kea: modify 'subnet6' section to increase pool size, e.g., 'pool': '2001:db8::/64' to '2001:db8::/56'
   ```
2. **In systemd-networkd: add 'IPv6AcceptRA=yes' to the .network file and remove DHCPv6 settings.** (75% success)
   ```
   In systemd-networkd: add 'IPv6AcceptRA=yes' to the .network file and remove DHCPv6 settings.
   ```

## Dead Ends

- **Removing the rapid-commit option from the DHCPv6 client configuration to force a four-message exchange.** — The server still has no addresses to assign; the four-message exchange will also fail with a NoAddressAvailable status. (90% fail)
- **Extending the default-lease-time to reduce address exhaustion.** — Does not create new addresses; if the pool is exhausted, longer leases only delay the problem. (70% fail)