Thanks for your reply ！
But what puzzles me is that I cannot login in my Jetson via ssh at all，while the pc and TX1 could ping both side successfully.(yean ,I am a rookie in ssh command/doge)
The commond is ：
ssh -v ubuntu(Jetson usrname)@*****（Jetson IP）
and return error of debug info like ：
lxy@ubuntu:~$ ssh -v ubuntu@Jetson IP
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to Jetson IP [Jetson IP] port 22.
debug1: Connection established.
debug1: identity file /home/lxy/.ssh/id_rsa type -1
debug1: identity file /home/lxy/.ssh/id_rsa-cert type -1
debug1: identity file /home/lxy/.ssh/id_dsa type -1
debug1: identity file /home/lxy/.ssh/id_dsa-cert type -1
debug1: identity file /home/lxy/.ssh/id_ecdsa type -1
debug1: identity file /home/lxy/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/lxy/.ssh/id_ed25519 type -1
debug1: identity file /home/lxy/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1p1 Ubuntu-2ubuntu2
debug1: match: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 pat OpenSSH_6.6.1* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
Connection closed by Jetson IP
Which folder contains the usful info(or log) in system?
The ssh_config is defualt (/etc/ssh/sshd_config),MTU both is 1500
What I should do next for locating the details of this error and resolve it?
Looking forward to your reply@linuxdev