const connection = mysql.createConnection({
host: `12.34.56.78/MSSQLSERVER2016`,
user: 'dbuser',
password: 'pwd',
database: 'DBNAME'
});

Error { Error: getaddrinfo ENOTFOUND 12.34.56.78MSSQLSERVER2016 12.34.56.78MSSQLSERVER2016:3306
    at errnoException (dns.js:50:10)
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:91:26)
    --------------------
    at Protocol._enqueue (/home/sultan/Desktop/testMysql/node_modules/mysql/lib/protocol/Protocol.js:145:48)
    at Protocol.handshake (/home/sultan/Desktop/testMysql/node_modules/mysql/lib/protocol/Protocol.js:52:23)
    at Connection.connect (/home/sultan/Desktop/testMysql/node_modules/mysql/lib/Connection.js:130:18)
    at Object.<anonymous> (/home/sultan/Desktop/testMysql/app.js:13:12)
    at Module._compile (module.js:569:30)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:503:32)
    at tryModuleLoad (module.js:466:12)
    at Function.Module._load (module.js:458:3)
    at Function.Module.runMain (module.js:605:10)
  code: 'ENOTFOUND',
  errno: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: '12.34.56.78MSSQLSERVER2016',
  host: '12.34.56.78MSSQLSERVER2016',
  port: 3306,
  fatal: true }