This read-write RipAuthKey (0..16 bytes), which per its source description always reads back as a zero-length string regardless of what's configured (authentication may not be bypassed by reading it), holds the actual authentication key used when zhRip2IfConfAuthType is set to something other than noAuthentication; shorter strings are left-justified and null-padded to 16 bytes. Admins set this to a shared secret matching what neighboring routers use for RIP authentication, understanding that changing zhRip2IfConfAuthType alone doesn't reset or clear this key value. For example, an admin rotating the RIP authentication key across a network would need to explicitly write a new value here on every participating router, since simply switching AuthType off and back on would not clear the old key.