VyOS currently supports only ICMP-based ping for connectivity testing. In many production environments, ICMP is filtered by firewalls while TCP traffic is permitted. This makes the standard 'ping' command useless for testing reachability to services such as BGP TCP-179, HTTP TCP-80, HTTPS (TCP/443), or any other hosted applications.

The current workaround requires external tools such as ncat, hping3, or telnet

nc -zv 255.255.255.255 179
sudo hping3 -S -p 179 255.255.255.255 -c 3
telnet 255.255.255.255 179

Neither tool is available by default in VyOS, and neither integrates with VRF-aware routing.

"The proposed operational command would be."

ping tcp <hostname|IPv4|IPv6> port <port>

With optional parameters consistent with the existing ping command:

ping tcp <host> port <port> count <n>
ping tcp <host> port <port> interface <ifname>
ping tcp <host> port <port> vrf <name>
ping tcp <host> port <port> source-address <address>

Use cases:
Confirming service| applications availability (HTTP, HTTPS, BGP, NTP, DNS, etc) from the router.
Troubleshooting in environments where ICMP is filtered or rate-limited.