Rollback from SONiC to IOS XR OS

This section describes how to rollback from SONiC OS to Cisco IOS XR Software on fixed (Cisco 8101, Cisco 8102) series of routers.

Before you begin

Complete these prerequisites before you install Cisco IOS XR Software on a router running SONiC OS:

Set up DHCP or PXE server to host the 8000-x64.iso IOS XR image.
Ensure that chassis can access the DHCP or PXE server hosting the IOS XR image.

Perform the following steps to rollback from SONiC to IOS XR OS:

Migrate RP from SONiC to IOS XR Software.

a. On the RP SONiC prompt, switch to privilege mode. Router cisco@sonic:~$ sudo bash b. Run the following commands from the console prompt based on the router. Router reload -r now
c. Press the ESC key continuously to interrupt the RP boot and enter the BIOS Boot Manager menu. Select iPXE from the menu. The router boots into the iPXE mode.
```Router Boot Manager

Boot Option Menu EFI Boot Devices SONiC OS (INTEL SSDSCKLB150G7) ONIE: Open Network Install Environment (INTEL SSDSCKLB150G7) iPXE ^ and v to change option, ENTER to select an option, ESC to exit
```
RP automatically downloads the 8000-x64.iso IOS XR image from the configured PXE server. The IOS XR install process starts to install the image on RP and reboot the RP       for the new image to take effect.
 
```
Check the image version on the RP
```
Router#show version
```
View the cards present on the chassis.
```
Router#show platform
```