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Cisco 1800 Series Routers (Modular) Hardware Installation Guide
OL-5876-03
Chapter 2 Overview of Cisco 1800 Series Routers (Modular)
Hardware Features
•
Boot/NVRAM—Serves two functions. It stores the ROM monitor, which allows you to boot an
operating system software image from flash memory. It also stores the system configuration file and
the virtual configuration register.
Table 2-3
lists the memory specifications for Cisco 1800 series routers.
Note
SDRAM and the flash memory are user-upgradable, but the boot/NVRAM is permanently soldered to
the router’s motherboard and is not upgradable.
LED Indicators
Table 2-5
summarizes the LED indicators for the Cisco 1841 router that are located in the router bezel
or chassis, but not in the interface cards.
For descriptions of the LEDs in the interface cards, see
Cisco Interface Card Installation Guide
.
Table 2-3
Router Memory Specifications for the Cisco 1841 Router
Description
Specification
SDRAM
128 MB, expandable to 384 MB; default is 128 MB
Flash memory
32, 64, or 128 MB; default is 32MB
Boot/NVRAM
2/4 MB flash memory
Table 2-4
Router Memory Specifications for the Cisco 1861 ISR
Description
Specification
DRAM
512 MB
Flash memory
128 MB
Table 2-5
Summary of Cisco 1800 Series LED Indicators
LED
Color
Description
Location:
SYS PWR
Green
Router has successfully booted and the software is functional.
This LED blinks while booting or in the ROM monitor.
Front
SYS ACT
Green
Blinking when any packets are transmitted or received on any
WAN or LAN, or when monitoring system activity.
Front
CF
Green
On when flash memory is busy. Do not remove the CompactFlash
memory card when this light is on.
Back
FDX (FE 0/0)
Green
On indicates full-duplex operation. Off indicates half-duplex
operation.
Back
100 (FE 0/0)
Green
On indicates a 100-Mbps link. Off indicates a 10-Mbps link.
Back
Link (FE 0/0)
Green
On when the router is correctly connected to a local Ethernet
LAN through Ethernet port 0.
Back
FDX (FE 0/1)
Green
On indicates full-duplex operation. Off indicates half-duplex
operation.
Back