A system performs upgrade of a network that includes network devices that provide connectivity to servers. The system performs network upgrade by evaluating a set of upgrade criteria for each network device to determine whether to upgrade the device or delay upgrading the network device. Each upgrade criterion is based on a relation between the selected network device and other network devices currently being upgraded. After completing the upgrade, the system determines whether the network upgrade completed successfully. The system determines whether the network upgrade completed successfully by determining a pre-snapshot representing a state of the network before network upgrade and a post-snapshot representing a state of the network after network upgrade. The system compares the pre-snapshot and the post-snapshot to determine whether the network upgrade completed successfully.