Administrator Guide

OSPFv3 Authentication Using IPsec: Conguration Notes
OSPFv3 authentication using IPsec is implemented according to the specications in RFC 4552.
• To use IPsec, congure an authentication (using AH) or encryption (using ESP) security policy on an interface or in an OSPFv3
area. Each security policy consists of a security policy index (SPI) and the key used to validate OSPFv3 packets. After IPsec is
congured for OSPFv3, IPsec operation is invisible to the user.
– You can only enable one security protocol (AH or ESP) 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.
– The security policy congured for an area is inherited by default on all interfaces in the area.
– The 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 (SAs) 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.
• Manual key conguration is supported in an authentication or encryption policy (dynamic key conguration using the internet key
exchange [IKE] protocol is not supported).
• In an OSPFv3 authentication policy:
– AH is used to authenticate OSPFv3 headers and certain elds in IPv6 headers and extension headers.
– MD5 and SHA1 authentication types are supported; encrypted and unencrypted keys are supported.
• In an OSPFv3 encryption policy:
– Both encryption and authentication are used.
– IPsec security associations (SAs) are supported only in Transport mode (Tunnel mode is not supported).
– ESP with null encryption is supported for authenticating only OSPFv3 protocol headers.
– ESP with non-null encryption is supported for full condentiality.
– 3DES, DES, AES-CBC, and NULL encryption algorithms are supported; encrypted and unencrypted keys are supported.
NOTE: To encrypt all keys on a router, use the service password-encryption command in Global Conguration
mode. However, this command does not provide a high level of network security. To enable key encryption in an IPsec
security policy at an interface or area level, specify
7 for [key-encryption-type] when you enter the ipv6 ospf
authentication ipsec or ipv6 ospf encryption ipsec command.
• To congure an IPsec security policy for authenticating or encrypting OSPFv3 packets on a physical, port-channel, or VLAN
interface or OSPFv3 area, perform any of the following tasks:
– Conguring IPsec Authentication on an Interface
– Conguring IPsec Encryption on an Interface
– Conguring IPSec Authentication for an OSPFv3 Area
– Conguring IPsec Encryption for an OSPFv3 Area
– Displaying OSPFv3 IPsec Security Policies
Conguring IPsec Authentication on an Interface
To congure, remove, or display IPsec authentication on an interface, use the following commands.
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 (refer to Conguration Task List for OSPFv2 (OSPF for
IPv4)).
The SPI value must be unique to one IPsec security policy (authentication or encryption) on the router. Congure the same
authentication policy (the same SPI and key) on each OSPFv3 interface in a link.
• Enable IPsec authentication for OSPFv3 packets on an IPv6-based interface.
INTERFACE mode
ipv6 ospf authentication {null | ipsec spi number {MD5 | SHA1} [key-encryption-type] key}
566
Open Shortest Path First (OSPFv2 and OSPFv3)