HIP Record Experimental

The HIP record (Host Identity Protocol) stores cryptographic host identifiers and associated IP addresses in DNS. Defined in RFC 8005, HIP enables identifier-locator separation, where a host's identity is distinct from its network location.

What Is a HIP Record?

HIP (Host Identity Protocol) separates the roles of IP addresses into:

• Host Identity — Cryptographic identifier for the host
• Locator — IP addresses where the host can be reached

This separation enables mobility, multi-homing, and enhanced security. The HIP record publishes the Host Identity Tag (HIT) and associated rendezvous servers or locators.

HIP Record Format

example.com.    3600    IN    HIP    2 200100107B1A74DF... AwEAAcNR... rvs.example.com.

HIP Record Fields

Public Key Algorithms

How HIP Works

1. Client queries DNS for HIP record of target host
2. Receives HIT (Host Identity Tag) and public key
3. If RVS provided, contacts rendezvous server
4. Establishes HIP connection using cryptographic handshake
5. Communication continues using HIP overlay

HIP Use Cases

Mobile Devices

HIP enables seamless roaming as device IP changes:

mobile.example.com.    HIP    2 200100107B1A74DF... AwEAAcNR... rvs.example.com.

Multi-Homed Servers

Servers with multiple network connections maintain consistent identity:

server.example.com.    HIP    2 200100107B1A74DF... AwEAAcNR...

Enhanced Security

Cryptographic identity prevents IP spoofing and enables IPsec-like security.

HIP Components

HIP Benefits

• Mobility — Connections survive IP address changes
• Multi-homing — Use multiple network interfaces seamlessly
• Security — Cryptographic authentication of hosts
• NAT traversal — Works through NAT with RVS
• Privacy — Can use temporary HITs

HIP Best Practices

• Use DNSSEC — Sign HIP records to prevent spoofing.
• Deploy RVS — Rendezvous servers help with NAT traversal.
• Keep keys secure — Protect the private key of the HI.
• Monitor deployment — HIP has limited adoption; verify support.

HIP Adoption

While HIP provides elegant solutions to IP mobility and multi-homing, adoption remains limited due to:

• Complexity — Requires changes to networking stack
• Alternative solutions — QUIC, MPTCP address similar needs
• Limited software support — Few applications use HIP
• Deployment challenges — Requires infrastructure changes

Troubleshooting HIP

Common issues and solutions:

• Record not found — HIP records are rare; most domains don't have them.
• Connection fails — Verify both ends support HIP.
• RVS unreachable — Check rendezvous server is operational.
• Key mismatch — Ensure HIT matches the public key.

Related Record Types

• A Record — IPv4 locator
• AAAA Record — IPv6 locator
• IPSECKEY Record — IPsec keys
• SSHFP Record — SSH fingerprints