Check the network status in Photon OS
To know how your network is configured (btw: default is DHCP) run the following command:
Define a static IP address in Photon
To change the default network settings from DHCP to a fixed IP move the network DHCP file and change the content (see sample below), then restart the network, before you can use ping see below "Install ping on Photon OS"
Reference: https://github.com/vmware/photon/blob/master/docs/photon-admin-guide.md#setting-a-static-ip-address
Install ping on Photon OS
I understand the need to keep Photon as small as possible, but certainly ping is a command we will need...