Netbooting
Netbooting is a common network administration tool. You run a small piece of
software called a TFTP server (trivial file transfer protocol) on any networked
PC and store your IOS on the hard drive. The router is configured to boot IOS
from that PC across the network. This is a method to use for booting up a
version of IOS that's larger than you have the flash to store. It's also a
great way to save your configurations and various code releases. If you want to
get serious about networking, you should learn to use netboot and TFTP. Cisco
has free software for TFTP at http://cio.cisco.com.
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Copy Configuration File(s) to TFTP:
router# copy running-config tftp
router# copy startup-config tftp
Copy Configuration File(s) from TFTP:
router# copy tftp running-config
router# copy tftp startup-config
Copy IOS to Router from TFTP:
router# copy tftp flash
Save IOS from Flash RAM to TFTP Server:
router# show flash (to find filename)
router# copy flash tftp
Save IOS from Flash RAM to TFTP Server (2600):
copy c2600-12-3.xxxx.bin tftp://10.253.15.72
Boot IOS from TFTP Server:
router(config)# boot system tftp IOS-filename tftp-server-ip-address
boot from FLASH memory (to change back?)
router(config)# boot system flash IOS-filename
boot from system ROM (emergency?)
router(config)# boot system rom
Startup-config via TFTP on Boot: (does this work?)
router(config)# boot host tftp startup-config-beta 192.168.4.251
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Using Cisco Router as TFTP Server
This configuration can be used to reload an IOS from another Cisco router. This
is useful when using the same model routers and you run the same IOS on each
one, or if you have lost the original IOS binary.
main#show flash
main#configure terminal
main(config)#tftp-server flash:c2500-p7-l.121-22b.bin
router(boot)#copy tftp flash
System flash directory:
File Length Name/status
1 8013396 c2500-i-l.121-15.bin
[8013460 bytes used, 375148 available, 8388608 total]
Address or name of remote host [10.50.0.254]? 10.51.0.3
Source file name? c2500-p7-l.121-22b.bin
Destination file name [c2500-p7-l.121-22b.bin]?
Accessing file 'c2500-p7-l.121-22b.bin' on 10.51.0.3...
Loading c2500-p7-l.121-22b.bin from 10.51.0.3 (via Serial0.112): ! [OK]
Erase flash device before writing? [confirm]y
Flash contains files. Are you sure you want to erase? [confirm]y
Copy 'c2500-p7-l.121-22b.bin' from server
as 'c2500-p7-l.121-22b.bin' into Flash WITH erase? [yes/no]yes
Erasing device... eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee ...erased
Loading c2500-p7-l.121-22b.bin from 10.51.0.3 (via Serial0.112): !!..
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The file must ALREADY exist in /home/tftp/* and be writable before you can
save it from the router.