VPNs are almost always over UDP.
See IPSec (most common VPN implementation): https://www.cloudflare.com/learning/network-layer/what-is-ip...
See Wireguard (increasing popularity): https://www.wireguard.com/
See IPSec (most common VPN implementation): https://www.cloudflare.com/learning/network-layer/what-is-ip...
See Wireguard (increasing popularity): https://www.wireguard.com/
TCP is protocol 6, UDP protocol 17; while IPsec uses protocol 50 for ESP (encrypted) and 51 for AH (authenticated).