TCP authentication option (TCP-AO) for BGP and LDP connections

You can use TCP-AO to authenticate TCP segments exchanged during BGP and LDP sessions. It supports both IPv4 and IPv6 traffic. TCP-AO provides a framework to support multiple stronger algorithms, such as HMAC-SHA1 and AES-128, to create its message digest. TCP-AO supports up to 64 keys that can be used for a BGP or an LDP session. You can configure a new key for a BGP or LDP session during its lifetime without causing any session flap. Each key becomes active based on its configured start time. In earlier releases, you could use only the TCP MD5 authentication method. It supports only MD5 algorithm to create its message digest.