Core issue
After upgrading Cisco IOS Software, certain lines of configuration (displayed in the output of the show running-config command in earlier software versions) may not show up in later software versions.
This might be due to changes in the default values in the later software. Some commands (enabled by default in earlier software) are disabled by default in later software. The reverse is also true.
Resolution
Although the default commands are applied and working, they may not be seen in the running configuration.
Non-default configurations are normally displayed in the running configuration.
For example, if the service config command is disabled by default, issuing either the show running-config or show startup-config commands will not display the no service config line.
However, if the service config command is issued, it appears in the output of the show running-config command and, if the configuration is saved, in the output of the show startup-config command.
This is a sample command output showing this concept:
c3548XL#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
c3548XL(config)#service config
c3548XL(config)#^Z
c3548XL#show run
Building configuration...
Current configuration:
!
version 12.0
service config
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
c3548XL#wr mem
Building configuration...
[OK]
c3548XL#show start
Using 2610 out of 32768 bytes
!
version 12.0
service config
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
c3548XL#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
c3548XL(config)#no service config
c3548XL(config)#^Z
c3548XL#wr mem
Building configuration...
[OK]
c3548XL#show run
Building configuration...
Current configuration:
!
version 12.0
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
c3548XL#show start
Using 2595 out of 32768 bytes
!
version 12.0
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
These are other possible reasons these commands may not appear:
- The feature set of the new Cisco IOS Software version does not support the features in older Cisco IOS Software versions. Be sure that the feature set is the same as the earlier code and that no features have been removed in the later code. If a feature is not supported, the commands associated with the feature are rejected, and the % Invalid input detected at '^' marker. messages will be seen for those commands at startup or during manual configuration.
For information on feature support, refer to the release notes.
- The new software does not support all the hardware. If certain interfaces are not recognized, the configuration for the interfaces will be rejected, and the % Invalid input detected at '^' marker. messages are seen for those commands at startup or during manual configuration.
To ensure all hardware is supported in the later version of the software, refer to the release notes.
For additional information about hardware and software compatibility, refer to Software Advisor.
