Cisco 3900 Series Integrated Services Routers (ISR), designed to power the next phase of branch-office evolution, offers unparalleled total cost of ownership savings and network agility through the intelligent integration of security, wireless, and application services.
As a popular Cisco router item, Cisco 3900 series offers an upgradable motherboard which allows owners to update hardware as more powerful options become available without having to purchase a new router. Cisco also appeals to environmentally conscious consumers with their EngeryWise dual power supplies, which lower electricity costs and support essential redundancy requirements. It is occasionally necessary to reset this powerful networking device, restoring it to factory default settings.
To reset a Cisco 3900 router, e.g. Cisco 3925, Cisco 3945, some Cisco 3900 users have discussed it like that:
About “3945 router password recovery”
Question:
“Hi There,
I understand that the password has to be changed the first time we login to Cisco 3945 router but i failed to do that and it’s not allowing me to connect using default username/password.
Can someone help me in getting this addressed??” —From vnirmal112
Answers from others
“You can but you don’t have to change the password the first time you login to the 3900. Are you trying to connect using the console port or telnet?”
“Logged onto router via console…was about to configure a new router…I got a clear message saying that i cannot login next time if i don’t change password, which i saw after logging off only :-(…”
“I am running 12.4.24. If you have another flash card, you can put a different IOS on it and boot it with that and see if you can get in. The other thing you can do is to try the password recovery and see if you can get in that way. Did you ever assign any passwords to it?”
Also frustrated with this Cisco 3900 resetting? Instructions help you reset Cisco 3900 series in detail
Method One
1. Enter “config-register 0x2102” from the router’s command prompt window. This gives you access to global configuration mode.
2. Enter “show version.” The response should read:
router# configure terminal
router (config) #config-register 0x2102
router (config) #end
router#
Repeat the “show version” command.
The response should now read “will be 0x2102 at next reload.”
3. Enter the command “write erase.” This will erase the current start-up configuration.
4. Reload the software by entering the “reload” command. Do not save when prompted.
The system display should read:
router#reload
System configuration has been modified. Save? (yes/no): n
Proceed with reload? (confirm)
Confirm that you want the reload to proceed.
5. Wait for the reload. The dialog box will read:—System Configuration Dialog—
Would you like to enter the initial configuration dialog? (yes/no)
The router has been reset.
Method Two
1. Enter the command “config-register 0x2142.”
The response should read:
Router (config)#config-register 0x2142
Repeat the “show version command.”
The response should now read “will be 0x2142 at next reload.”
2. Reload the software by entering the “reload” command. Do not save when prompted. The system should read:
router#reload
System configuration has been modified. Save? (Yes/no): n
Proceed with reload? (Confirm)
Confirm that you want the reload to proceed.
3. Wait for the reload. The dialog box will read:
—System Configuration Dialog—
Would you like to enter the initial configuration dialog? (Yes/no) Enter “no.”
4. Change the configuration register setting to 0x2102. Enter “config-register 0x2102.” Enter “write memory.” This will overwrite the running configuration.
5. Enter the “reload” command. The system configuration dialog will appear again. The router is reset.
