Memory Configurations
3
Hardware Installation Guide
2-3
Hardware User’s Guide
2.2
Memory Configurations
The CRBRIM-W/E has the following memory systems:
•
Primary memory (main memory)—Dynamic random-access memory
(DRAM) that stores the running configuration and routing tables; mounted on
the system card.
•
Shared memory—Shared DRAM that is used for packet buffering by the
router network interfaces.
•
System-code memory—Flash or programmable read-only memory (PROM);
stores the operating system software image.
•
Boot ROM memory—Stores a subset of the operating system software image
that is called the system bootstrap image or the bootstrap program (or ROM
monitor). The system bootstrap image allows you to boot the router when
Flash memory does not contain a valid system image.
The boot ROM prompt follows: Router(boot)>. The bootstrap program (ROM
monitor) prompt is the greater than sign (>), which differs from the user-level
operating-system prompt of gateway >. (For more information, see Appendix
B, “Virtual Configuration Register,” and Appendix C, “Bootstrap Program.”
•
Nonvolatile random-access memory (NVRAM)—Stores the system
configuration file and the virtual configuration register.
