Firmware upgrade path
Any 5.0.x release
↓
5.0.5 (Build 0188)
↓
5.3.23 (Build 0449)
↓
6.0.4 (Build 0193)
After every upgrade, verify that the build number and version number match the image that was loaded. To do so, go to Dashboard > Status.
Note: For FortiVoice 2000E-T2 with serial number prefix of FO2HDD, if upgrade is done through "G" option of boot loader, FVE-200D platform image should be used.