The term “deleted sub interfaces” refers to virtual interfaces that have been removed from a network device, usually a router or switch. A virtual interface is a logical representation of a physical interface, such as an Ethernet or Fiber channel connection. It is used to configure multiple connections on a single physical interface, allowing for more efficient use of the device’s resources.
When a virtual interface is removed from the device, it is still present in the Non-Volatile RAM (NVRAM) of the device. This is because the NVRAM contains the configuration settings for the device, and when a virtual interface is removed, the settings for that interface remain in the NVRAM. This can cause issues when attempting to add a new virtual interface to a device because the old interface settings may conflict with the new one.
The first step in getting rid of deleted sub interfaces from NVRAM is to identify which interfaces are no longer in use. This can be done by examining the output of the show interface command on the device. This command will list all of the active and inactive interfaces on the device, and any deleted sub interfaces should be listed as inactive.
Once the deleted sub interfaces have been identified, they should be removed from the device’s configuration using the no interface command. This command will delete the configuration settings for the interface from the NVRAM, allowing the new interface to be configured without any conflicts.
Finally, the device should be reset to ensure that all of the changes have taken effect. This can be done by issuing the reload command, which will reboot the device. Once the device has restarted, the deleted sub interfaces should no longer be present in the NVRAM.
In summary, the process of getting rid of deleted sub interfaces from NVRAM involves identifying the interfaces, deleting them from the device’s configuration, and resetting the device. This process ensures that the configuration settings for the device remain consistent, and that new interfaces can be configured without any conflicts.