How to archive and retrieve configuration on the router in case of lost config

Rt1#config t
Rt1(config)#archive
Rt1(config-archive)# path flash:/config-archive/$h-config
Rt1(config-archive)# wr
Rt1(config-archive)#time-period 10080
Rt1(config-archive)#end

you can also configure the archive to trigger a backup any time the running configuration is saved to the NVRAM and also every 10080 minutes (one week).



Rt1#sho archive
there are curently 1 archive configuration save.
the next archive file will be named config-archive/Rt1-config-4
archive # name
0
1           flash: /config-archive/Rt1-config-1
2          flash: /config-archive/Rt1-config-2
3          flash: /config-archive/Rt1-config-3 <--Most Recent
4
5
6

Rt1# configure replace flash:config-archive/Rt1-config-3 list
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: 0

Rollback Done