The prompt tells you that the router has not booted using the IOS from the FLASH but only a small backup IOS from the router's ROM. This mode is called the BootROM mode. A 2500 series router boots into the BootROM mode either if the IOS in the FLASH is erased or corrupted, or if the configuration register value is changed so that it directs the router to go into the BootROM.
Try to enter the command show flash to see if the proper IOS is stored in the FLASH. Also verify using the command show version that the configuration register value is set to 0x2102. If the IOS is missing from the FLASH you will need to download it there (you will need a PC running a TFTP server software for that, and obviously, the IOS itself). If the configuration register value is different from 0x2102 you will have to correct it by entering the command config-register 0x2102 in the global configuration mode. Do not save the configuration after you change the configuration register value - the change is applied immediately, and saving the configuration may in fact store a corrupted version, as the IOS in the ROM does not recognize all commands for a full IOS version, and is not able to write them in a new configuration file.
Also, using the show startup-config, try to check if there are any commands of the boot system form in the configuration file. If they are misspelled they may again cause the router to fail booting the full IOS. In such a case, set the configuration register to the value 0x2142, reload the router (it will boot into the full IOS but will ignore the stored configuration). Then use the command copy startup-config running-config to activate the stored configuration. In the global configuration mode, remove the boot system commands and return the configuration register value back to 0x2102. Then you may store the configuration using the command write and reload the router. You may also need to correct other parts of the configuration (such as activating the interfaces, as they will remain in a shutdown state).
Both options are possible - that either the image or the FLASH itself is corrupted.
Yes, the BootROM IOS image does not support the FTP protocol. The only option is to use TFTP. If you are running Linux on your workstation I can heartily recommend the atftpd software - a very good TFTP server implementation. You can install it using your favourite package manager. If you are running Windows then perhaps the Kiwi TFTP server from the Kiwi CatTools package will do for you. You can download the software here:
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...