Installation guide

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Cisco 1750 Router Hardware Installation Guide
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Router Memory
Router Memory
This section describes the types of memory stored in the router and how to find
out how much of each the router has.
For instructions on how to upgrade memory in the router, refer to the “Installing
and Upgrading Memory and Data Modules” appendix in this guide.
Types of Memory
The router has the following types of memory:
• Dynamic RAM (DRAM)—This is the main storage memory for the router.
DRAM is also called working storage and contains the dynamic configuration
information. The router stores a working copy of Cisco IOS software,
dynamic configuration information, and routing table information in DRAM.
• Nonvolatile RAM (NVRAM)—This type of memory contains the startup
configuration.
• Flash memory—This special kind of erasable, programmable memory
contains a copy of the Cisco IOS software. The Flash memory structure can
store multiple copies of the Cisco IOS software. You can load a new level of
the operating system in every router in your network and then, when
convenient, upgrade the whole network to the new level. The Flash memory
on the router is stored on mini-Flash modules.