wget --user=YOUR_EMAIL --password=YOUR_PASSWORD \ "https://customerconnect.vmware.com/download/..." But due to session cookies, it's easier to download via browser, then scp or sftp the ISO to your server. After downloading, verify the checksum (available on the download page):
VMware vSphere Free Trial
SHA256: 1234abcd... (check official site) For scripting or older releases: esxi download
VMware Customer Connect - ESXi Free