Cisco 2811 ROUTER 2FE 1NME 4HWIC 2PVDM 2AIM IP BASE WITH A/C POWER SUPPLY Specification Guide

Cisco 2800 series routers contain the following types of memory:

DRAM—Stores the running configuration and routing tables and is used for packet buffering by the 
network interfaces. Cisco IOS software executes from DRAM memory. 

Boot/NVRAM—Internal flash memory. Stores the bootstrap program (ROM monitor), the 
configuration register, and the startup configuration.

Flash memory—External flash memory. Stores the operating system software image.

 summarizes the memory options for Cisco 2800 series routers. The default memory numbers for 

RAM represent the minimum usable memory. You can install additional RAM in multiples of the default 
amount, up to the maximum amount.

Cisco 2801

Type—SDRAM DIMM

DIMM sizes—64 MB, 128 MB, 256 MB

DIMM expansion slots—1

1

Default onboard memory—128 MB

Maximum memory—384 MB

1.

Cisco 2801 routers have 128 MB of SDRAM soldered onto the system board. You can install a DIMM into the expansion slot 
to increase memory to the maximum of 384 MB.

Internal 4-MB 
flash memory

External CompactFlash 
memory cards of the 
following optional 
sizes:

64 MB (default)

128 MB

Cisco 2811

Type—ECC DDR (error-correcting code, 
double data rate) SDRAM DIMM

DIMM sizes—256 MB

DIMM slots—2

Default memory—256 MB

Maximum memory—768 MB

2

2.

Cisco 2811 routers can accept two 256 MB DIMMs to provide 768 MB of usable memory.

Internal 2-MB 
flash memory

External CompactFlash 
memory cards of the 
following optional 
sizes:

64 MB (default)

128 MB

256 MB

Cisco 2821

Type—ECC DDR (error-correcting code, 
double data rate) DRAM DIMM

DIMM sizes—256 MB

DIMM slots—2

Default memory—256 MB

Maximum memory—1024 MB

Cisco 2851