OSPFv2 HMAC SHA-2 keychain authentication and weighted ECMP

You can use this feature to ensure a smooth transition from one key to another for OSPFv2 with enhanced security. 

Use this feature with an OSPFv2 keychain module with HMAC-SHA2 authentication to authenticate packets reaching or originating from an OSPF interface. HMAC SHA2 algorithms include HMAC-SHA2-256, HMAC-SHA2-384 and HMACSHA2-512 as defined in RFC 5709, OSPFv2 HMAC-SHA Cryptographic Authentication. We also support the HMAC-SHA2-224 algorithm or HMAC-SHA1 and HMAC-SHA2 authentication for virtual and sham links.