diff --git a/cmd.go b/cmd.go
index 89e5a68..7018ca6 100644
--- a/cmd.go
+++ b/cmd.go
@@ -24,35 +24,52 @@ func (c *Connect) Command(command string) (err error) {
 	}
 	defer func() { c.Session = nil }()
 
-	// setup options
-	err = c.setOption(c.Session)
-	if err != nil {
-		return
-	}
-
-	// Set Stdin, Stdout, Stderr...
-	if c.Stdin != nil {
+	// Set Stdin
+	switch {
+	case c.Stdin != nil:
 		w, _ := c.Session.StdinPipe()
 		go io.Copy(w, c.Stdin)
-	} else {
+
+	case c.PtyRelayTty != nil:
+		c.Session.Stdin = c.PtyRelayTty
+
+	default:
 		stdin := GetStdin()
 		c.Session.Stdin = stdin
 	}
 
-	if c.Stdout != nil {
+	// Set Stdout
+	switch {
+	case c.Stdout != nil:
 		or, _ := c.Session.StdoutPipe()
 		go io.Copy(c.Stdout, or)
-	} else {
+
+	case c.PtyRelayTty != nil:
+		c.Session.Stdout = c.PtyRelayTty
+
+	default:
 		c.Session.Stdout = os.Stdout
 	}
 
-	if c.Stderr != nil {
+	// Set Stderr
+	switch {
+	case c.Stderr != nil:
 		er, _ := c.Session.StderrPipe()
 		go io.Copy(c.Stderr, er)
-	} else {
+
+	case c.PtyRelayTty != nil:
+		c.Session.Stderr = c.PtyRelayTty
+
+	default:
 		c.Session.Stderr = os.Stderr
 	}
 
+	// setup options
+	err = c.setOption(c.Session)
+	if err != nil {
+		return
+	}
+
 	// Run Command
 	c.Session.Run(command)
 
diff --git a/connect.go b/connect.go
index d4affed..d55b211 100644
--- a/connect.go
+++ b/connect.go
@@ -6,7 +6,6 @@ package sshlib
 
 import (
 	"context"
-	"errors"
 	"io"
 	"log"
 	"net"
@@ -51,6 +50,9 @@ type Connect struct {
 	// Set it before CraeteClient.
 	ForwardAgent bool
 
+	// Set the TTY to be used as the input and output for the Session/Cmd.
+	PtyRelayTty *os.File
+
 	// CheckKnownHosts if true, check knownhosts.
 	// Ignored if HostKeyCallback is set.
 	// Set it before CraeteClient.
@@ -191,36 +193,37 @@ func (c *Connect) SendKeepAlive(session *ssh.Session) {
 		interval = c.SendKeepAliveInterval
 	}
 
+	max := 3
+	if c.SendKeepAliveMax > 0 {
+		max = c.SendKeepAliveMax
+	}
+
 	t := time.NewTicker(time.Duration(c.ConnectTimeout) * time.Second)
 	defer t.Stop()
 
+	count := 0
 	for {
 		select {
 		case <-t.C:
 			if _, err := session.SendRequest("keepalive@openssh.com", true, nil); err != nil {
-				if !errors.Is(err, io.EOF) {
-					log.Println("Failed to send keepalive packet:", err)
-					session.Close()
-					c.Client.Close()
-					break
-				} else {
-					// sleep
-					time.Sleep(time.Duration(interval) * time.Second)
-					continue
-				}
+				log.Println("Failed to send keepalive packet:", err)
+				count += 1
 			} else {
-				// sleep
+				// err is nil.
 				time.Sleep(time.Duration(interval) * time.Second)
-				continue
 			}
 		}
+
+		if count > max {
+			return
+		}
 	}
 }
 
 // CheckClientAlive check alive ssh.Client.
 func (c *Connect) CheckClientAlive() error {
 	_, _, err := c.Client.SendRequest("keepalive", true, nil)
-	if err == nil || err.Error() == "request failed" {
+	if err == nil {
 		return nil
 	}
 	return err
diff --git a/shell.go b/shell.go
index e9379a5..a185947 100644
--- a/shell.go
+++ b/shell.go
@@ -20,7 +20,13 @@ import (
 // Shell connect login shell over ssh.
 func (c *Connect) Shell(session *ssh.Session) (err error) {
 	// Input terminal Make raw
-	fd := int(os.Stdin.Fd())
+	var fd int
+	if c.PtyRelayTty != nil {
+		fd = int(c.PtyRelayTty.Fd())
+	} else {
+		fd = int(os.Stdin.Fd())
+	}
+
 	state, err := terminal.MakeRaw(fd)
 	if err != nil {
 		return
@@ -33,6 +39,13 @@ func (c *Connect) Shell(session *ssh.Session) (err error) {
 		return
 	}
 
+	// set tty
+	if c.PtyRelayTty != nil {
+		session.Stdin = c.PtyRelayTty
+		session.Stdout = c.PtyRelayTty
+		session.Stderr = c.PtyRelayTty
+	}
+
 	// Start shell
 	err = session.Shell()
 	if err != nil {
@@ -42,6 +55,11 @@ func (c *Connect) Shell(session *ssh.Session) (err error) {
 	// keep alive packet
 	go c.SendKeepAlive(session)
 
+	// if tty is set, get signal winch
+	if c.PtyRelayTty != nil {
+		go c.ChangeWinSize(session)
+	}
+
 	err = session.Wait()
 	if err != nil {
 		return
@@ -54,7 +72,13 @@ func (c *Connect) Shell(session *ssh.Session) (err error) {
 // Used to start a shell with a specified command.
 func (c *Connect) CmdShell(session *ssh.Session, command string) (err error) {
 	// Input terminal Make raw
-	fd := int(os.Stdin.Fd())
+	var fd int
+	if c.PtyRelayTty != nil {
+		fd = int(c.PtyRelayTty.Fd())
+	} else {
+		fd = int(os.Stdin.Fd())
+	}
+
 	state, err := terminal.MakeRaw(fd)
 	if err != nil {
 		return
@@ -67,6 +91,13 @@ func (c *Connect) CmdShell(session *ssh.Session, command string) (err error) {
 		return
 	}
 
+	// set tty
+	if c.PtyRelayTty != nil {
+		session.Stdin = c.PtyRelayTty
+		session.Stdout = c.PtyRelayTty
+		session.Stderr = c.PtyRelayTty
+	}
+
 	// Start shell
 	err = session.Start(command)
 	if err != nil {
@@ -84,6 +115,23 @@ func (c *Connect) CmdShell(session *ssh.Session, command string) (err error) {
 	return
 }
 
+func (c *Connect) ChangeWinSize(session *ssh.Session) {
+	// Get terminal window size
+	var fd int
+	if c.PtyRelayTty != nil {
+		fd = int(c.PtyRelayTty.Fd())
+	} else {
+		fd = int(os.Stdout.Fd())
+	}
+	width, height, err := terminal.GetSize(fd)
+	if err != nil {
+		return
+	}
+
+	// Send window size
+	session.WindowChange(height, width)
+}
+
 // SetLog set up terminal log logging.
 // This only happens in Connect.Shell().
 func (c *Connect) SetLog(path string, timestamp bool) {