56 Chapter 2: Cisco Internetwork Operating System (IOS) Fundamentals
Figure 2-13 summarizes the use of memory in Cisco routers.
Figure 2-13
Cisco Router Memory Types
Figure 2-14 illustrates the relationships among configuration mode, user EXEC mode, and
priviledged EXEC mode.
Figure 2-14
CLI Configuration Mode Versus EXEC Modes
The copy command is used to move configuration files among RAM, NVRAM, and a TFTP
server. The files can be copied between any pair, as Figure 2-15 illustrates.
Figure 2-15
Locations for Copying and Results from Copy Operations
RAM
(Working
Memory)
Flash
(IOS)
ROM
(IOS)
NVRAM
(Config)
User EXEC Mode
Privileged EXEC
Mode
Configuration
Mode
RAM
(Active Config)
each command
enable
in succession
Ctrl-Z
or
exit
config t
RAM
TFTP
NVRAM
Merge
Merge
Replace
Replace
Replace
Replace
ch02.fm Page 56 Monday, March 20, 2000 4:57 PM