Transcript Cisco S2 C7 - YSU Department of Computer Science and

Cisco S2 C7
Router Operation System
IOS
Routers Boot From
• Flash memory
• TFTP server
• ROM (not full Cisco IOS software)
– Default depends on platform
– Order can be programmed by user
Boot Sequence
• Boot system Flash IOS_filename
• Boot system TFTP IOS_filename tftp
address
• Boot system ROM IOS_filename
Register Values
• 0x..0
Use ROM (boot manually – use b
command)
• 0x…1
Automatically boot from ROM (is
default if router has no flash)
• 0x…2 to 0x…F
– Examine NVRAM
– Default if router has Flash memory
• Use config-register in global configuration to
change the default setting
• Use show version command to verify configregister command
Show Version Screen Display
• System image file is "c4500-f-mz", booted via
tftp from 171.69.1.129
• Also displays information about the type of
platform on which the version of Cisco IOS
software is currently running
• Displays information about the Cisco IOS
software version that is currently running
• Shows configuration register and the boot field
setting
Bootstrap Options
• Router # configure terminal
• Router (config) # boot system flash gsnewimage
– Ctrl+Z
• Router #
TFTP
• Router # ping tftp – address
–
–
–
–
Sending 5, 100-byte ICMP echoes to IP add
Timeout is __ seconds !!!.!
Success rate is 80% (4/5)
Round trip min/avg/max = 45/54/160 ns
• Show flash
• Shows free flash memory
• Ls
• List of directories and file names used on tftp server
Show Flash
• Verifies sufficient memory to load IOS
• Displays
– Amount of flash memory
– Amount of free memory
– Status
• Should backup IOS image for each router
Cisco Naming Conventions
• Name
hw platform features
Run location
• Cpa25-cg-1 2500
Remote Acc
reloc
• Igs-inr-1
25xx
IP subset IPX reloc
• Naming convention has three parts
– Platform, letter or series of letters, where image runs
and if it is compressed or zipped
Copy Flash
• provide a fallback copy of the current
image prior to updating the image with a
new version
• erase routine is usually required before new
files can be copied.
• Each exclamation point (!) means that one
User Datagram Protocol (UDP) segment has
successfully transferred
Copy tftp flash
• Used to load backup IOS version
• System will prompt for IP address of tftp
server
• System will prompt for file name of image
• File with same same in flash will be deleted
when you copy
– DELETED files listed with deleted tag when
you use show flash command