In order to back up the IOS you need a TFTP server, SolarWinds offers a Free TFTP Server.
If you have no idea what version of the IOS you are using use the show flash command.
Router#show flash System flash directory: File Length Name/status 1 3289170 d1206.bin [3289236 bytes used, 905068 available, 4194304 total] 4096K bytes of processor board System flash (Read/Write)
Backup
From the console in privileged EXEC mode enter the copy flash tftp command. When requested enter the IP address of the TFTP server.
Router#copy flash tftp Source filename []? d1205.bin Address or name of remote host []? 192.168.1.21 Destination filename [d1205.bin]? y !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 3289170 bytes copied in 47.668 secs (69982 bytes/sec)
Restore
To copy the IOS from a TFTP server use the copy tftp command. When requested enter the IP address of the TFTP server containing the IOS.
Router#copy tftp flash Address or name of remote host []? 192.168.1.21 Source filename []? d1206.bin Destination filename [d1206.bin]? Accessing tftp://192.168.1.21/d1206.bin... Erase flash: before copying? [confirm] Erasing the flash filesystem will remove all files! Continue? [confirm] Erasing device... eeeeeeeeeeeeeeee ...erased Erase of flash: complete Loading d1206.bin from 192.168.1.21 (via Ethernet0): !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! [OK - 3289170/6578176 bytes] Verifying checksum... OK (0xB6BD) 3289170 bytes copied in 89.272 secs (36956 bytes/sec)
