Using Tamir.SharpSsh;

SshExec exec = new SshExec("ip address", "username", "password");
exec.Connect();
var output = exec.RunCommand("show vlan");
exec.Close();

using Renci.SshNet;
 using (var client = new SshClient(Host, UserName, Password))
        {
            try
            {
                client.Connect();
            }
            catch (Exception ex)
            {

                throw;
            }

            var command = client.CreateCommand("show vlan");
            return command.Execute();
        }