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Tim Glen
Cisco Employee
Cisco Employee


Traditionally Cisco has used several different methods for storing passwords and keys in IOS.  The older methods are Type 5 (MD5 hash) & Type7 (Vigenere obfuscation). We enabled Type 7 encryption with the CLI service password-encryption command.

There are some newer methods like Type 8 (SHA256) and Type 9 (SCRYPT). At this time my recommendation is to never use Type 5 or Type 7 and absolutely do not EVER use Type 4.   


Today in 2021 the recommendation is to use Type 6, Type 8 and Type 9. Type 6 use strong AES 128-bit encryption for storing passwords. If you interested in the details for Types 0,4,5,6,7,8,9 please check out this other document I wrote. I’d like to make a counting joke here but I won’t.


Note: Using Type 6 has been supported since 2006, IOS 12.3(2)T and possibly earlier! 


For a detailed explanation of each password type please see this document I wrote. 



In this example I’m working with devices that have reset to factory defaults.

  • Catalyst 9300 with IOS XE 17.3(3)

 Any device that runs modern IOS XE should support Type 6




Configuration Steps

1. Enable AES 128 password encryption

configure terminal
  password encryption aes
  key config-key password-encrypt super-secret-password


Managing the Keys

The super-secret-password you used is very important.  It's very important that you store the key somewhere offline.  Be sure to keep in it KeePass, or 1Password or the password vault of your choice. Optimally each device you configure Type 6 on will have a unique Key.


Changing the Password

There shouldn’t be too many reasons to change the password key. However, if you have the old password key, changing it is an easy task with no negative effects.

password key change example.png




These need to be reviewed \ changed.

Look into running config for Type 7 Passwords

show running-config | include _7_


Look into running config for Type 5 Passwords

show running-config | include _5_



These are safe to use.

Look into running config for Type 6 Passwords

show running-config | include _6_


Look into running config for Type 8 Passwords

show running-config | include _8_


Look into running config for Type 9 Passwords

show running-config | include _9_




Q: Should we leave service password-encryption in the config?

A: Yes, while it shouldn’t be needed because we’ve enabled Type 6 passwords, leaving service password-encryption in the running config will cause any other Type 5 or Type 7 passwords to be obfuscated instead of being stored in the clear.



Q: Should I store the key ?

A: YES, the key should DEFINITELY be stored.  In the event that you need to move this devices config to a new device you will need the key.



Q: What passwords will be converted?

A: According to my tests the following passwords and password types will be converted:

  • TACACS server keys (previously in Type 7)
  • RADIUS server keys (previously in Type 7)
  • vty login passwords (previously in Type 7)


Q: What password types will NOT be converted?

A: According to my tests the following passwords and password types will be NOT be converted:

  • enable secret 9
  • BGP MD5 authentication password, instead use BGP TCP Authentication Option
  • OSPF MD5 authentication password, instead use HMAC Authentication
  • HSRP \ VRRP using key-string for authentication,  instead use authentication key-chain which will convert to Type 6



Q: Can you revert to non-Type 6 passwords?

A: Reverting to non-Type 6 is a manual process.

First, identify all type 6 passwords

Then issue

no password-encryption aes

Then, revert each of the previously identified Type 6 and reconfigure.



Q: What happens if I need to change the password encryption key?

A: This is typically not needed, however, if you still have the password, good, no problem!  Just change it, see the above example.

Q: What happens if I lose the password encryption key?

A: Moving the passwords in their encrypted form to a new box will be impossible.

Q: What happens if I lose the password encryption key and need to change the password encryption key?

A: I'd call Cisco TAC

Q: Where should I look for changes in the running-config?

A: Typically, I’ve seen Type 5 and Type 7 passwords in the following places:

  • username kashvi password …
  • enable password
  • RADIUS key
  • TACACS key
  • VTY login
  • BGP peer password
  • MKA preshared key

Q: Can I implement password encryption aes on an existing switch?

A: Yes, of course!   Please use the verification commands above to assure that all of your legacy passwords especially Type 5 and Type 7 are converted to the newer Type 6.

Q: I’m deploying a new switch \ router, how should it be configured?

A: Use the configuration script above right from the start. There is no need to use service password-encryption. 

Q: In the event I need to use Type 8 or Type 9 which is more secure?

A: Both Type 8 and Type 9 are secure, feel comfortable using either. 

Q: I don’t see key config-key password-encrypt in the running config…

A: Yes, you shouldn’t. Keeping the key in clear text would be insecure as it may provide a means to decrypt the passwords. The key is stored in a partition that is not accessible by the administrator.

Q: Can I configure Type 6 encryption on my router if my BGP, OSPF, EIGRP peer router doesn’t support it.

A: Yes!  Because the routing protocol’s process on your router will decrypt the password before using it with the peer this should not be a problem.  

Q: Should I be using enable password or enable secret?

A: Definitely use enable secret. If both are configured only enable secret is used.



Cisco IOS XE Command Reference (key config-key password-encrypt)

Cisco IOS XE Command Reference (password encryption aes)

Encrypt Pre-shared Keys in Cisco IOS Router Configuration

Cisco IOS Command Reference (service password-encryption)




Pierce Vasale

Thank you! This is awesome! (Especially alongside your linked document going over the differences.)

Tim Glen
Cisco Employee
Cisco Employee

Thanks for the compliment @Pierce Vasale  !   Glad you like and hope it helps in your network!


Thank you Tim, it´s working perfectly on Cat9XXX Switches.

But have you any idear how to change the password type to 6 on cat 2960X Switch, especially the keys in the Radius and TACACs section? Because it´s working for the username password but not for the Radius and TACACs Key... I have to remove the keys in the section and create a new key 6 entry and the hash I got from a working 9XXX Switch. But I don´t think this is the correct way to do it, right?

Tim Glen
Cisco Employee
Cisco Employee

@adrian.smithson  what IOS version are you using on the 2960X? 


@Tim Glen  I am running 15.2.7E2 on my 2960X

Tim Glen
Cisco Employee
Cisco Employee



No, I don't think the way you are doing it with the 2960 is the way to do it.  I'm actually a little surprised it is converting your username password combo.  I just tried the same with a 3750X w IOS 15.2(4)E7 and nothing was converted, not the username password and not the RADIUS or TACACS keys.  


I've done a little research and I've found this.
Features Introduced in Cisco IOS Release 15.2(7)E3
Support for Type 6 AES Encryption password: Beginning with this release, you can specify a Type 6 encrypted key for a TACACS Server. The new command is tacacs server key 6 key-name.


I'm not 100% sure but as far as I can tell from some research,  Type 6 was introduced back in mid-2000s to help secure the shared secret in IOS VPN config.


Then as time went on Cisco introduced other encryption algorithms (Type 4,8,9) and slowly rolled the Type 6 into other functions like username password,  RADIUS key & TACACS key. 


Hope this helps & sorry for the delay in answering. 



@Tim Glen 
Hi Tim,

I had some time to take a closer look on this...

I tested with 2960X 15.2(7)E4 and 15.2(7)E5 and I can confirm with 15.2(7)E5 everything is working as expected like you described for a 9300.

With 2960X 15.2(7)E4 there is no way that the TACACS Key or RADIUS Key get changed to Key 6...  Can´t find any information in the release notes but 15.2(7)E5 works great.


Adrian S.



@Tim Glen 

Do you have any idea why your instructions do not work on a C1000-8P-E-2G-L with 15.2(7)E6? The switch does not know the command "password encryption aes" nor "key config-key password-encrypt" in config mode.

Hi Tim, great post, very informative.  I know there hasn't been any comments on this for a little while, but got a question I'm hoping someone can answer.


I'm wanting to convert all my type 7 password right now and trying to figure out the best way to go about this.   I want to use type 8 or 9 for my local "username" passwords and type 6 for my radius shared keys (as type 8/9 is not available for radius shared keys).  Is this possible to use both in the same switch config?


If you can use both, and I've already converted my "username" command passwords to type 8 or 9, will entering the "password encryption aes" and  "key config-key password-encrypt super-secret-password" commands convert those username password to type 6 or will it continue to use type 8/9 for "username" and only convert the radius shared keys to type 6? 


You may have already answered this in the Q&A in you post and pasting below, but just wanted to confirm what to expect.  Sounds like it should keep the local "username" passwords as 8 or 9 and only convert my radius server keys? 

Q: What passwords will be converted?

A: According to my tests the following passwords and password types will be converted:

  • TACACS server keys (previously in Type 7)
  • RADIUS server keys (previously in Type 7)
  • vty login passwords (previously in Type 7)


Thank you in advance.

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