Reference Guide

OSPFv3 IPsec authentication and encryption
Unlike OSPFv2, OSPFv3 does not have authentication elds in its protocol header to provide security. To provide authentication and
condentiality, OSPFv3 uses IP Security (IPsec) — a collection of security protocols for authenticating and encrypting data packets. OS10
OSPFv3 supports IPsec using the IPv6 authentication header (AH) or IPv6 encapsulating security payload (ESP).
• AH authentication veries that data is not altered during transmission and ensures that users are communicating with the intended
individual or organization. The authentication header is inserted after the IP header with a value of 51. MD5 and SHA1 authentication
types are supported; encrypted and unencrypted keys are supported.
• ESP encryption encapsulates data, enabling the protection of data that follows in the datagram. The ESP extension header is inserted
after the IP header and before the next layer protocol header. 3DES, DES, AES-CBC, and NULL encryption algorithms are supported;
encrypted and unencrypted keys are supported.
Apply IPsec authentication or encryption on a physical, port-channel, or VLAN interface or in an OSPFv3 area. Each conguration consists
of a security policy index (SPI) and the key used to validate OSPFv3 packets. After you congure an IPsec protocol for OSPFv3, IPsec
operation is invisible to the user.
You can only enable one security protocol (authentication or encryption) at a time on an interface or for an area. Enable IPsec AH with the
ipv6 ospf authentication command; enable IPsec ESP with the ipv6 ospf encryption command.
• A security policy congured for an area is inherited by default on all interfaces in the area.
• A security policy congured on an interface overrides any area-level congured security for the area to which the interface is assigned.
• The congured authentication or encryption policy is applied to all OSPFv3 packets transmitted on the interface or in the area. The
IPsec security associations are the same on inbound and outbound trac on an OSPFv3 interface.
• There is no maximum AH or ESP header length because the headers have elds with variable lengths.
Congure IPsec authentication on interfaces
Prerequisite: Before you enable IPsec authentication on an OSPFv3 interface, rst enable IPv6 unicast routing globally, congure an IPv6
address and enable OSPFv3 on the interface, and assign it to an area.
The SPI value must be unique to one IPsec security policy (authentication or encryption) on the router. You cannot congure the same SPI
value on another interface even if it uses the same authentication or encryption algorithm.
You cannot use an IPsec authentication type (MD5 or SHA-1) and the null setting at same time on an interface. These settings are
mutually exclusive.
• Enable IPsec authentication for OSPFv3 packets in Interface mode.
ipv6 ospf authentication {null | ipsec spi number {MD5 | SHA1} key}
• null — Prevent an authentication policy congured for the area to be inherited on the interface. This parameter is only used if you
congure IPsec area authentication.
• ipsec spi number — Enter a unique security policy index (SPI) value (256 to 4294967295).
• md5 — Enable message digest 5 (MD5) authentication.
• sha1 — Enable secure hash algorithm 1 (SHA-1) authentication.
• key — Enter the text string used in the authentication type. All neighboring OSPFv3 routers must share the key to exchange
information. Only a non-encrypted key is supported. For MD5 authentication, the non-encrypted key must be 32 plain hex digits.
For SHA-1 authentication, the non-encrypted key must be 40 hex digits. An encrypted key is not supported.
To delete an IPsec authentication policy, use the no ipv6 ospf authentication ipsec spi number or no ipv6 ospf
authentication null command.
Congure IPsec authentication on interface
OS10(conf-if-eth1/1/1)# ipv6 ospf authentication ipsec spi 400 md5
12345678123456781234567812345678
378
Layer 3