To replace the current running configuration with a saved Cisco IOS configuration file, use the configure replace command in privileged EXEC mode.
Router#configure replace flash:test.cfg
This command will replace (NOTE: not merge) the running config with the config in file test.cfg. This command was introduced in 12.3(7)T
Here is an example of the effect:
Router#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 10.10.10.3 YES manual up up
FastEthernet0/1 10.1.1.1 YES manual up up
Serial0/3/0 unassigned YES unset administratively down down
Router#configure replace flash:test.cfg
This will apply all necessary additions and deletions
to replace the current running configuration with the
contents of the specified configuration file, which is
assumed to be a complete configuration, not a partial
configuration. Enter Y if you are sure you want to proceed. ? [no]: y
Total number of passes: 1
Rollback Done
r1#
Dec 18 00:44:05.927: Rollback:Acquired Configuration lock.
Dec 18 00:44:07.703: %PARSER-3-CONFIGNOTLOCKED: Unlock requested by process ’3′.
Configuration not locked.
Dec 18 00:44:08.819: %LINK-5-CHANGED: Interface FastEthernet0/1, changed state to administratively down
r1#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 10.10.10.3 YES manual up up
FastEthernet0/1 10.1.1.1 YES manual administratively down down
Serial0/3/0 unassigned YES unset administratively down down
NOTE the following:
1) Router name has changed
2) FastEthernet 0/1 no longer has an IP address
3) FastEthernet 0/1 is shutdown
This is great as rather than just MERGING a config, the command REPLACES the config. You can replace the running-config from many places:
r1#configure replace ?
archive: URL of config file that will replace running-config
cns: URL of config file that will replace running-config
flash: URL of config file that will replace running-config
ftp: URL of config file that will replace running-config
http: URL of config file that will replace running-config
https: URL of config file that will replace running-config
null: URL of config file that will replace running-config
nvram: URL of config file that will replace running-config
pram: URL of config file that will replace running-config
rcp: URL of config file that will replace running-config
scp: URL of config file that will replace running-config
system: URL of config file that will replace running-config
tftp: URL of config file that will replace running-config
xmodem: URL of config file that will replace running-config
ymodem: URL of config file that will replace running-config
You could thus have a backup config in flash or on a TFTP server and restore immediately to running config.
Author: David Bombal
Article Source: EzineArticles.com
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