Authentication Header - IP Protocol
This page provides IP protocol information on the Authentication Header IP protocol (AH) detected by the Netify DPI engine. Please see the IP protocol catalog for information on other IP protocols.
AH is the Authentication Header, the IPsec protocol that provides connectionless integrity and data-origin authentication for IP packets, without encryption. Linux has a native handler for this IP protocol.
IP Protocol Details
- Name
- Authentication Header
- Abbreviation
- AH
- Status
- Active
- IANA Number
- 51
- IANA Keyword
- AH
- Reference
- Authentication Header
IP Protocol Status - Active
AH was standardized in RFC 4302 (2005) and remains defined and supported, though ESP is far more commonly deployed in practice today.
IP Protocol Network Policy
AH is used for IPsec traffic requiring integrity and authentication without encryption; allow only on hosts or gateways configured for AH-mode IPsec, which is uncommon today.