Configuring Authentication of CSNPs and PSNPs

You must enable and disable authentication of CSNP packets and PSNP packets separately from authentication of LSP packets.

area-authentication

Use to enable or disable (suppress) simple authentication or HMAC MD5 authentication of IS-IS level 1 CSNP packets or PSNP packets.
When authentication is enabled, it uses either the simple text password specified by the area-authentication-key command, or the HMAC MD5 key specified by the area-message-digest-key command.
You must specify either the csnp keyword to enable authentication of level 1 CSNP packets, or the psnp keyword to enable authentication of level 1 PSNP packets.
Examplehost1(config-router)#area-authentication csnp
Use the no version to restore the default behavior, in which authentication of level 1 CSNPs and PSNPs is disabled. When authentication of level 1 CSNPs or PSNPs is suppressed, the router does not authenticate these packets when it receives them, nor does it send authentication information in these packets when it transmits them.
See area-authentication

domain-authentication

Use to enable or disable (suppress) simple authentication or HMAC MD5 authentication of IS-IS level 2 CSNP packets or PSNP packets.
When authentication is enabled, it uses either the simple text password specified by the domain-authentication-key command, or the HMAC MD5 key specified by the domain-message-digest-key command.
You must specify either the csnp keyword to enable authentication of level 2 CSNP packets, or the psnp keyword to enable authentication of level 2 PSNP packets.
Examplehost1(config-router)#domain-authentication csnp
Use the no version to restore the default behavior, in which authentication of level 2 CSNPs and PSNPs is disabled. When authentication of level 2 CSNPs or PSNPs is suppressed, the router does not authenticate these packets when it receives them, nor does it send authentication information in these packets when it transmits them.
See domain-authentication