This article addresses the issue of MX204 booting up in 'Amnesiac' mode due to "mgd: error: configuration check-out failed" after a failed SW upgrade. This problem is encountered when there is some incorrect configuration present on the device and customer uses the 'no-validate' option during VMHOST upgrade.

• VMHOST software upgrade is performed on MX204 using the 'no-validate' option.
• The device boots up in 'Amnesiac' mode with partial configuration.
• The device is accessible on console but not via SSH/Telnet.
• Root credentials don't work.
• The following error messages are seen in the console logs.

In the example below, the config check-out failed due to identical IPv6 addresses configured on xe-0/1/5.0 and xe-0/1/6.0.

</snip>
mgd: error: configuration check-out failed
Warning: Failed to commit active configuration.
Warning: Trying to commit recovery mode configuration.
Interface control process: <xnm:error xmlns="http://xml.juniper.net/xnm/1.1/xnm" xmlns:xnm="http://xml.juniper.net/xnm/1.1/xnm">
Interface control process: <source-daemon>dcd</source-daemon>
Interface control process: <edit-path>[edit interfaces xe-0/1/6 unit 0 family inet6]</edit-path>
Interface control process: <statement>address xxxx:xxxx::xxx:xxxx:xxx/123</statement>
Interface control process: <message> identical local address found on rt_inst [default], intfs [xe-0/1/6.0 and xe-0/1/5.0], family [inet6].</message>
Interface control process: </xnm:error>
<snip/>

Solution:-

> Rollback the software version using "request vmhost software rollback <>".
> Rectify the incorrect configuration.
> Reattempt the SW upgrade without using the 'no-validate' option.