this is checking:

• ping via IPv4 and IPv6
• http connection to various FQDNs
• expiration of SSL certificates

check host host.domain.tld with address host.domain.tld 
        if failed ping4 then alert
        if failed ping6 then alert
        
        # ISPConfig
        if failed
                  port 8080
                  protocol https
                  and certificate valid > 3 days
        then alert
        
        # generic domain
        if failed url https://host.domain.tld/
                  with timeout 15 seconds
                  and certificate valid > 3 days
        then alert
        
        # Roundcube
        if failed 
                  port 443
                  protocol https
                  request /webmail/
                  with timeout 15 seconds
                  and certificate valid > 3 days
                  content = "The Roundcube Dev Team"
        then alert
        group connectivity

~~DISCUSSION~~