Functions of the SC
The Sun Fire 15K SC is responsible for managing the overall Sun Fire 15K frame. The following list is an overview of the many services the SC provides for the Sun Fire 15K system:
Manages the overall system configuration.
Acts as a boot initiator for its domains.
Serves as the syslog host for its domains; note that an SC can still be a syslog client of a LAN-wide syslog host.
Provides a synchronized hardware clock source.
Sets up and configures dynamic domains.
Monitors system environmental information, such as power supply, fan, and temperature status.
Hosts Field Replacable Unit (FRU) logging data.
Provides redundancy and automated SC failover in dual SC configurations.
Provides a default name service for the domains based on NIS+, virtual hostids, and MAC addresses for the domains.
Provides administrative roles for frame management.
Clearly, the SC provides many critical functions for the Sun Fire 15K system. The domains will not operate properly if a controlling SC is absent. Therefore, preserving the security of the SC is very important.
From a hardware perspective, the output of uname on an SC provides the following:
# uname -i SUNW,UltraSPARC-IIi-cEngine # uname -m sun4u
This information is similar to the output of any other sun4u class server.
The Sun Fire 15K frame supports up to two SCs. The first SC (sc0) is referred to as the main SC, while the other SC (sc1) is referred to as the spare. The software running on the SC monitors the SCs to determine if an automatic failover should be performed. The two SCs should have the same configuration. This duplication of configuration should include the Solaris OE installation, security modifications, patch installations, and all other aspects of system configuration.
The failover functionality between the SCs is controlled by the daemons running on the main and spare SCs. These daemons communicate across a private network built into the Sun Fire 15K frame. Other than the communication of these daemons, there is no special trust relationship between the two SCs.
System Management Services (SMS) Software
Another significant aspect to the security of the SC is access to the various applications which an administrator uses to manage a Sun Fire 15K system. Some of the security issues associated with the software that controls these applications, called the System Management Services (SMS), are discussed in the System Management Services (SMS) 1.1 Administrative Guide. This article builds on the recommendations made in the SMS Security chapter of that guide.
Access to the SMS software is the core of the SC. Correspondingly, access to this software must be carefully controlled and only authorized accounts should have access. The SMS software provides a mechanism, over and above the Solaris OE access controls, to limit access to the SMS software. These features are described in the Default SC SMS Software Configuration section below.