[CAUSE] The tBgp4OptTransPathAttrInvalid notification is generated when the received optional-transitive path attribute is unknown to this BGP peer. This notification was obsoleted in R11.0 and replaced with the notification tBgp4PathAttrInvalid. [EFFECT] The BGP peer simply passes the path attribute to the next BGP peer along the route and is not considered responsible for any encoding error. In this case the BGP peering is not torn down. [RECOVERY] There is no recovery required for this notification.