Reports status of PunSSH tunnels and the SSH public keys they are using.

The table provides the following information per 'item':

• id (int) Unique id
• serial_number (string) Serial Number
• destination (string) Address of the SSH jump host / tunnel concentrator
• name (string) Tunnel name
• status (string) One of absent, ready, error, up
• pubkey (string) The SSH public key