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Level 1

8 points

xterm: Xt error: Can't open display: xterm: DISPLAY is not set

Hello, I am completely new to networking/systems. I have been asked to complete an open flow tutorial ( http://www.openflow.org/wk/index.php/OpenFlow_Tutorial ) I have fininshed a part of the tutorial and when i used "ssh -X mininet@192.168.**.*", I was able to log in successfully but when i type in Xterm, it says "xterm: Xt error: Can't open display: xterm: DISPLAY is not set". I have downloaded virtual box, XQuartz and an ovf file as given in teh tutorial. I don't know what the problem is. Can someone please guide me through this? Thank you so much!

MacBook Pro, OS X Mountain Lion (10.8.2)

Posted on May 17, 2013 10:23 AM

Best reply

BobHarris

Level 9

53,309 points

Posted on May 17, 2013 10:27 AM

Did you logout and login after installing XQuartz? Or reboot?

Otherwise the DISPLAY environment variable will not be in your environment.

View in context

32 replies

shja Author

Level 1

8 points

May 18, 2013 9:16 PM in response to BobHarris

I have already made mininet an admin too. I have restarted the laptop after doing that and tried the sudo command again. no change.

shja Author

Level 1

8 points

May 18, 2013 9:28 PM in response to etresoft

I have downloaded virtual box and got the VM running. Infact, the VM is running right now. I have tried pinging the IP address. what should I do now?

etresoft

Level 8

46,654 points

May 18, 2013 9:30 PM in response to shja

shja wrote:

I have tried pinging the IP address. what should I do now?

And what is the result?

shja Author

Level 1

8 points

May 19, 2013 9:15 AM in response to etresoft

Last login: Sat May 18 17:09:45 2013 from 192.168.56.1

mobile-172-16-103-167:~ mininet$ ssh -Y mininet@192.168.56.1

Password:

Last login: Sat May 18 20:25:50 2013 from 192.168.56.1

mobile-172-16-103-167:~ mininet$ ping 192.168.56.1

PING 192.168.56.1 (192.168.56.1): 56 data bytes

64 bytes from 192.168.56.1: icmp_seq=0 ttl=64 time=0.068 ms

64 bytes from 192.168.56.1: icmp_seq=1 ttl=64 time=0.068 ms

64 bytes from 192.168.56.1: icmp_seq=2 ttl=64 time=0.090 ms

64 bytes from 192.168.56.1: icmp_seq=3 ttl=64 time=0.076 ms

64 bytes from 192.168.56.1: icmp_seq=4 ttl=64 time=0.073 ms

64 bytes from 192.168.56.1: icmp_seq=5 ttl=64 time=0.067 ms

64 bytes from 192.168.56.1: icmp_seq=6 ttl=64 time=0.072 ms

64 bytes from 192.168.56.1: icmp_seq=7 ttl=64 time=0.109 ms

64 bytes from 192.168.56.1: icmp_seq=8 ttl=64 time=0.118 ms

64 bytes from 192.168.56.1: icmp_seq=9 ttl=64 time=0.111 ms

It keeps going on and does not stop until i close the terminal.

etresoft

Level 8

46,654 points

May 19, 2013 11:13 AM in response to shja

Do you have any firewall running or anything? If so, shut it off.

Try the following:

ssh -v -v -Y mininet@192.168.56.1

It will spit out a bunch of stuff. Hopefully some of it is useful.

You might also try it without the "-v"s or even the "-Y". You aren't trying to follow the tutorial anymore. Now you are just debugging Linux and VirtualBox. Your quest is just to log on at this point. You are far, far away from ever getting an X windows connection.

shja Author

Level 1

8 points

May 19, 2013 11:14 AM in response to etresoft

mobile-172-16-103-167:~ SHREYA20$ ssh -v -v -Y mininet@192.168.56.1

OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011

debug1: Reading configuration data /etc/ssh_config

debug1: /etc/ssh_config line 20: Applying options for *

debug1: /etc/ssh_config line 53: Applying options for *

debug2: ssh_connect: needpriv 0

debug1: Connecting to 192.168.56.1 [192.168.56.1] port 22.

debug1: Connection established.

debug1: identity file /Users/SHREYA20/.ssh/id_rsa type -1

debug1: identity file /Users/SHREYA20/.ssh/id_rsa-cert type -1

debug1: identity file /Users/SHREYA20/.ssh/id_dsa type 2

debug1: identity file /Users/SHREYA20/.ssh/id_dsa-cert type -1

debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9

debug1: match: OpenSSH_5.9 pat OpenSSH*

debug1: Enabling compatibility mode for protocol 2.0

debug1: Local version string SSH-2.0-OpenSSH_5.9

debug2: fd 3 setting O_NONBLOCK

debug1: SSH2_MSG_KEXINIT sent

debug1: SSH2_MSG_KEXINIT received

debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie- hellman-group14-sha1,diffie-hellman-group1-sha1

debug2: kex_parse_kexinit: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa,ssh-dss-cert-v01@openssh.com,ssh-dss-cert-v00@openssh.com,ssh-dss

debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blow fish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se

debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96

debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib

debug2: kex_parse_kexinit:

debug2: kex_parse_kexinit: first_kex_follows 0

debug2: kex_parse_kexinit: reserved 0

debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie- hellman-group14-sha1,diffie-hellman-group1-sha1

debug2: kex_parse_kexinit: ssh-rsa,ssh-dss

debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blow fish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se

debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96

debug2: kex_parse_kexinit: none,zlib@openssh.com

debug2: kex_parse_kexinit:

debug2: kex_parse_kexinit: first_kex_follows 0

debug2: kex_parse_kexinit: reserved 0

debug2: mac_setup: found hmac-md5

debug1: kex: server->client aes128-ctr hmac-md5 none

debug2: mac_setup: found hmac-md5

debug1: kex: client->server aes128-ctr hmac-md5 none

debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP

debug2: dh_gen_key: priv key bits set: 121/256

debug2: bits set: 481/1024

debug1: SSH2_MSG_KEX_DH_GEX_INIT sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY

debug1: Server host key: RSA 9f:5f:6b:69:a9:6a:3b:39:71:dd:70:34:92:cd:c4:4b

debug1: Host '192.168.56.1' is known and matches the RSA host key.

debug1: Found key in /Users/SHREYA20/.ssh/known_hosts:2

debug2: bits set: 513/1024

debug1: ssh_rsa_verify: signature correct

debug2: kex_derive_keys

debug2: set_newkeys: mode 1

debug1: SSH2_MSG_NEWKEYS sent

debug1: expecting SSH2_MSG_NEWKEYS

debug2: set_newkeys: mode 0

debug1: SSH2_MSG_NEWKEYS received

debug1: Roaming not allowed by server

debug1: SSH2_MSG_SERVICE_REQUEST sent

debug2: service_accept: ssh-userauth

debug1: SSH2_MSG_SERVICE_ACCEPT received

debug2: key: /Users/SHREYA20/.ssh/id_rsa (0x0)

debug2: key: /Users/SHREYA20/.ssh/id_dsa (0x7f8328c1d200)

debug1: Authentications that can continue: publickey,keyboard-interactive

debug1: Next authentication method: publickey

debug1: Trying private key: /Users/SHREYA20/.ssh/id_rsa

debug1: Offering DSA public key: /Users/SHREYA20/.ssh/id_dsa

debug2: we sent a publickey packet, wait for reply

debug1: Authentications that can continue: publickey,keyboard-interactive

debug2: we did not send a packet, disable method

debug1: Next authentication method: keyboard-interactive

debug2: userauth_kbdint

debug2: we sent a keyboard-interactive packet, wait for reply

debug2: input_userauth_info_req

debug2: input_userauth_info_req: num_prompts 1

Password:

debug2: input_userauth_info_req

debug2: input_userauth_info_req: num_prompts 0

debug1: Authentication succeeded (keyboard-interactive).

Authenticated to 192.168.56.1 ([192.168.56.1]:22).

debug1: channel 0: new [client-session]

debug2: channel 0: send open

debug1: Requesting no-more-sessions@openssh.com

debug1: Entering interactive session.

debug2: callback start

debug2: Checking for xauth using /opt/X11/bin/xauth -f /var/folders/t_/qmb9xb0d7d50_0x4_4_yklm00000gn/T//xauth_test exit > /dev/null 2> /dev/null

debug2: x11_get_proto: /opt/X11/bin/xauth list /tmp/launch-Vw25Uu/org.macosforge.xquartz:0 2>/dev/null

debug1: Requesting X11 forwarding with authentication spoofing.

debug2: channel 0: request x11-req confirm 1

debug2: client_session2_setup: id 0

debug2: fd 3 setting TCP_NODELAY

debug2: channel 0: request pty-req confirm 1

debug1: Sending environment.

debug1: Sending env LANG = en_US.UTF-8

debug2: channel 0: request env confirm 0

debug2: channel 0: request shell confirm 1

debug2: callback done

debug2: channel 0: open confirm rwindow 0 rmax 32768

debug2: channel_input_status_confirm: type 100 id 0

X11 forwarding request failed on channel 0

debug2: channel_input_status_confirm: type 99 id 0

debug2: PTY allocation request accepted on channel 0

debug2: channel 0: rcvd adjust 2097152

debug2: channel_input_status_confirm: type 99 id 0

debug2: shell request accepted on channel 0

Last login: Sat May 18 20:26:04 2013 from 192.168.56.1

mobile-172-16-103-167:~ mininet$

etresoft

Level 8

46,654 points

May 19, 2013 6:47 PM in response to shja

Try ssh -v -v without the -Y. You are debugging Linux here. Baby steps.

shja Author

Level 1

8 points

May 19, 2013 6:50 PM in response to etresoft

If i type only ssh -v -v, this is what it is giving me

mobile-172-16-103-167:~ SHREYA20$ ssh -v -v

OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011

usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]

[-D [bind_address:]port] [-e escape_char] [-F configfile]

[-I pkcs11] [-i identity_file]

[-L [bind_address:]port:host:hostport]

[-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]

[-R [bind_address:]port:host:hostport] [-S ctl_path]

[-W host:port] [-w local_tun[:remote_tun]]

[user@]hostname [command]

shja Author

Level 1

8 points

May 19, 2013 6:50 PM in response to etresoft

i tried ssh -v -v mininet@192.168.56.1 and it showed me this:

mobile-172-16-103-167:~ SHREYA20$ ssh -v -v mininet@192.168.56.1

OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011

debug1: Reading configuration data /etc/ssh_config

debug1: /etc/ssh_config line 20: Applying options for *

debug1: /etc/ssh_config line 53: Applying options for *

debug2: ssh_connect: needpriv 0

debug1: Connecting to 192.168.56.1 [192.168.56.1] port 22.

debug1: Connection established.

debug1: identity file /Users/SHREYA20/.ssh/id_rsa type -1

debug1: identity file /Users/SHREYA20/.ssh/id_rsa-cert type -1

debug1: identity file /Users/SHREYA20/.ssh/id_dsa type 2

debug1: identity file /Users/SHREYA20/.ssh/id_dsa-cert type -1

debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9

debug1: match: OpenSSH_5.9 pat OpenSSH*

debug1: Enabling compatibility mode for protocol 2.0

debug1: Local version string SSH-2.0-OpenSSH_5.9

debug2: fd 3 setting O_NONBLOCK

debug1: SSH2_MSG_KEXINIT sent

debug1: SSH2_MSG_KEXINIT received

debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie- hellman-group14-sha1,diffie-hellman-group1-sha1

debug2: kex_parse_kexinit: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa,ssh-dss-cert-v01@openssh.com,ssh-dss-cert-v00@openssh.com,ssh-dss

debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blow fish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se

debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96

debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib

debug2: kex_parse_kexinit:

debug2: kex_parse_kexinit: first_kex_follows 0

debug2: kex_parse_kexinit: reserved 0

debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie- hellman-group14-sha1,diffie-hellman-group1-sha1

debug2: kex_parse_kexinit: ssh-rsa,ssh-dss

debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blow fish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se

debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96

debug2: kex_parse_kexinit: none,zlib@openssh.com

debug2: kex_parse_kexinit:

debug2: kex_parse_kexinit: first_kex_follows 0

debug2: kex_parse_kexinit: reserved 0

debug2: mac_setup: found hmac-md5

debug1: kex: server->client aes128-ctr hmac-md5 none

debug2: mac_setup: found hmac-md5

debug1: kex: client->server aes128-ctr hmac-md5 none

debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP

debug2: dh_gen_key: priv key bits set: 132/256

debug2: bits set: 493/1024

debug1: SSH2_MSG_KEX_DH_GEX_INIT sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY

debug1: Server host key: RSA 9f:5f:6b:69:a9:6a:3b:39:71:dd:70:34:92:cd:c4:4b

debug1: Host '192.168.56.1' is known and matches the RSA host key.

debug1: Found key in /Users/SHREYA20/.ssh/known_hosts:2

debug2: bits set: 525/1024

debug1: ssh_rsa_verify: signature correct

debug2: kex_derive_keys

debug2: set_newkeys: mode 1

debug1: SSH2_MSG_NEWKEYS sent

debug1: expecting SSH2_MSG_NEWKEYS

debug2: set_newkeys: mode 0

debug1: SSH2_MSG_NEWKEYS received

debug1: Roaming not allowed by server

debug1: SSH2_MSG_SERVICE_REQUEST sent

debug2: service_accept: ssh-userauth

debug1: SSH2_MSG_SERVICE_ACCEPT received

debug2: key: /Users/SHREYA20/.ssh/id_rsa (0x0)

debug2: key: /Users/SHREYA20/.ssh/id_dsa (0x7ffc1a41d1c0)

debug1: Authentications that can continue: publickey,keyboard-interactive

debug1: Next authentication method: publickey

debug1: Trying private key: /Users/SHREYA20/.ssh/id_rsa

debug1: Offering DSA public key: /Users/SHREYA20/.ssh/id_dsa

debug2: we sent a publickey packet, wait for reply

debug1: Authentications that can continue: publickey,keyboard-interactive

debug2: we did not send a packet, disable method

debug1: Next authentication method: keyboard-interactive

debug2: userauth_kbdint

debug2: we sent a keyboard-interactive packet, wait for reply

debug2: input_userauth_info_req

debug2: input_userauth_info_req: num_prompts 1

Password:

debug2: input_userauth_info_req

debug2: input_userauth_info_req: num_prompts 0

debug1: Authentication succeeded (keyboard-interactive).

Authenticated to 192.168.56.1 ([192.168.56.1]:22).

debug1: channel 0: new [client-session]

debug2: channel 0: send open

debug1: Requesting no-more-sessions@openssh.com

debug1: Entering interactive session.

debug2: callback start

debug2: client_session2_setup: id 0

debug2: fd 3 setting TCP_NODELAY

debug2: channel 0: request pty-req confirm 1

debug1: Sending environment.

debug1: Sending env LANG = en_US.UTF-8

debug2: channel 0: request env confirm 0

debug2: channel 0: request shell confirm 1

debug2: callback done

debug2: channel 0: open confirm rwindow 0 rmax 32768

debug2: channel_input_status_confirm: type 99 id 0

debug2: PTY allocation request accepted on channel 0

debug2: channel 0: rcvd adjust 2097152

debug2: channel_input_status_confirm: type 99 id 0

debug2: shell request accepted on channel 0

Last login: Sun May 19 13:14:33 2013 from 192.168.56.1

mobile-172-16-103-167:~ mininet$

etresoft

Level 8

46,654 points

May 19, 2013 7:15 PM in response to shja

OK. Now I am confused. Originally you were user SHREYA20 and now you are starting and ending as mininet.

Open a new terminal. Type "whoami" and press enter. Then type "hostname" and press enter.

Do ssh mininet@192.168.56.1

At the prompt, type "whoami" and press enter. Then type "hostname" and press enter.

I am beginning to suspect you logged in correctly and are now just running in a loop.

shja Author

Level 1

8 points

May 19, 2013 8:42 PM in response to etresoft

Last login: Sun May 19 20:48:05 on ttys001

mobile-172-16-103-167:~ SHREYA20$ whoami

SHREYA20

mobile-172-16-103-167:~ SHREYA20$ hostname

mobile-172-16-103-167.near.illinois.edu

mobile-172-16-103-167:~ SHREYA20$ ssh mininet@192.168.56.1

Password:

Last login: Sun May 19 20:48:40 2013 from 192.168.56.1

mobile-172-16-103-167:~ mininet$ whoami

mininet

mobile-172-16-103-167:~ mininet$ hostname

mobile-172-16-103-167.near.illinois.edu

mobile-172-16-103-167:~ mininet$

etresoft

Level 8

46,654 points

May 20, 2013 3:25 AM in response to shja

What you are doing is logging into the mininet account on your Mac. It must be Virtual Box that can't do the virtual network interface properly. On your Mac, go to System Preferences > Sharing and turn off remote login. Then restart your machine and try it again.

shja Author

Level 1

8 points

May 20, 2013 8:00 AM in response to etresoft

I have turned off the remote login and tried it:

Last login: Sun May 19 22:41:18 on ttys001

mobile-172-16-103-167:~ SHREYA20$ whoami

SHREYA20

mobile-172-16-103-167:~ SHREYA20$ hostname

mobile-172-16-103-167.near.illinois.edu

mobile-172-16-103-167:~ SHREYA20$ ssh mininet@192.168.56.1

ssh: connect to host 192.168.56.1 port 22: Connection refused

mobile-172-16-103-167:~ SHREYA20$

mobile-172-16-103-167:~ SHREYA20$ ssh -v -v mininet@192.168.56.1

OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011

debug1: Reading configuration data /etc/ssh_config

debug1: /etc/ssh_config line 20: Applying options for *

debug1: /etc/ssh_config line 53: Applying options for *

debug2: ssh_connect: needpriv 0

debug1: Connecting to 192.168.56.1 [192.168.56.1] port 22.

debug1: connect to address 192.168.56.1 port 22: Connection refused

ssh: connect to host 192.168.56.1 port 22: Connection refused

mobile-172-16-103-167:~ SHREYA20$

etresoft

Level 8

46,654 points

May 20, 2013 8:30 AM in response to shja

Go back and re-do the "Finish VM Setup" portion of the tutorial. Virtual Box is either not running or is not listening for connections correctly.

LKLin

Level 1

0 points

Jan 2, 2014 11:02 AM in response to shja

Hi shja,

I meet the same problem as you, did you solve this problem? Would you please tell me how to solve it?

Thank you!

xterm: Xt error: Can't open display: xterm: DISPLAY is not set