I just started a new position where none of the code is in version control. One of my duties is to fix that. I have some space on a SuSe 10 box, and subversion 1.6 is installed. Following the instructions in the O'Reilly Subversion book, I've got a subversion repository with code in it, and svnserve running:
#lsof -i :3690
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
svnserve 15115 xxxxxx 3u IPv6 xxxxxxxx TCP *:svn (LISTEN)
Also, this command works
svnlook cat /home/svn/repos/ /project1/trunk/index.php
However, when I try to connect to the subversion repository from my desktop (running Windows) using TortoiseSVN, I get the error
Can't connect to host 'xxx.xxx.xxx.xxx': A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
I have tried multiple repository URLs, including:
svn://internalmachinename.internalnetwork.com/project1
svn://machinename/project1
svn://machinename/repos/project1
svn://machinename/svn/repos/project1
svn://xxx.xxx.xxx.xxx/project1/trunk:3690
I don't have access to Cygwin because of the company's firewall policy, so I can't try to connect via the command line.
Before trying to use svn, use the simple ping command to check the connection between the two computers.
Only if that works, go to the next step (which still isn't using svn!): check if you can reach the correct port using telnet.
Then, and only then should you try to use svn to do the connection.
The firewall suggestion was close - it was the firewall on my Windows desktop that was keeping Subversion from connecting.
Related
I am using Mininet on a remote Ubuntu without GUI. And I am trying to use "xterm h1" to open a terminal on a virtual host in Mininet. But it showed me always there is no display connected. I am trying to use other X application like firefox and it showed me
"No protocol specified
Unable to init server: Could not connect: Connection refused
Error: cannot open display: :0.0"
Then I have set X11forward yes in sshd_config on the remote Ubuntu, and install Xlaunch on my windows but showed no changes.
Can someone tell me how to solve this problem?
PS. I am using a pycharm on Windows11 to establish this SSH session
Since you are running windows you will first need an application that will run an X11 server on your windows, Xming, for example. You will then need to configure your ssh connection to use that xserver. Finally you want to setup the DISPLAY variable at your remote to be LOCAL_IP:0 where LOCAL_IP is the public IP of your machine.
installed TigerVNC on Centos 8.3 and tried to run it with vncserver Command but it is giving me this message "vncserver has been replaced by a systemd unit."
I have also followed the instruction from this file /usr/share/doc/tigervnc/HOWTO.md and created a vnc session. the session is accessible only on loopback ip of the machine.
Result of : netstat -tulpn Command:
tcp 0 0 127.0.0.1:5905 0.0.0.0:* LISTEN 2645/Xvnc
tcp6 0 0 ::1:5905 :::* LISTEN 2645/Xvnc
how can i change loopback ip of vnc session to machine ip.
Minhaj:
I ran into this today. TigerVNC has been changed with the version 8.x Fedora kernel. I dug a bit & found it is related to "an upstream decision." What this means in simple English is that the project team made a design decision. I personally agree with the design changes since it brings greater control and security to VCN than previous versions. This is not to suggest the actual VNC protocol is SSL enabled. You should still employ best practices like using firewalld to prevent access to VCN ports and using SSH tunneling to get to the console, etc.
To get started, you'll need to do a bit of simple configuration work as described in /usr/share/doc/tigervnc/HOWTO.md. Start by reading the instructions in the file.
All tasks must be run with root priv, so use the sudo utility for all of them.
TASK 1: At the simplest level, begin by opening the file /etc/tigervnc/vncserver.users
Create an entry for each user that will use the service. For example:
:1=hwojteczko
:2=esong
Note the digit preceding each user name. This is the VNC console number that will be assigned to each user. Save the file.
TASK 2: Inspect the /usr/share/xsessions file to confirm the type of desktop installed on the system. The default desktop is gnome, but there are others, so be mindful of this.
TASK 3: Next, you'll need to modify the Xvnc options file. Fortunately, there are some commented entries already left in place, which can be removed. Open the file /etc/tigervnc/vncserver-config-defaults, remove the comments as shown below, but also add the desktop to the session config within the stanza. This will not likely be there, so it is easy to miss this step. See example below:
securitytypes=vncauth,tlsvnc
desktop=sandbox
geometry=2000x1200
localhost
alwaysshared
session=gnome
TASK 4: As the user, set a VNC password using vncpasswd . This will be similar to what you are accustomed to with previous versions of TigerVNC, but it WILL NOT start TigerVNC.
IMPORTANT: For the next task, you must make sure that you, or the user, is not logged into a desktop session. For those like me who develop code on Linux, this is an easy way to get tripped up. This is not a concern if you are accessing a remote server.
TASK 5: Start the VNC Service for the correct user session. See below:
systemctl start vncserver#:1
You'll see there is no output to speak of. Use sysctl and check the status. It is best to wait about 10-15 seconds before doing so to ensure the startup does not fail.
systemctl status vncserver#:1
TASK 6: Now, you can check to see that port 5901 is open with nmap, as in:
nmap -PN localhost
Which should report something like:
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
111/tcp open rpcbind
631/tcp open ipp
5901/tcp open vnc-1
now you can ssh to the host and tunnel VNC traffic securely, such as:
ssh hwojteczko#172.16.129.5 -N -L localhost:5901:localhost:5901
TASK 7: When you are done, don't forget to shutdown TigerVCN using systemctl, as in:
systemctl stop vncserver#:1
Happy coding......
h
My Cygwin installed on Windows 7 was working properly till I try to install a new package. The package installation failed. Then I keep getting this error every time I want to run my Open MPI program. I can successfully compile the program but cannot run it. I even remove and make a new installation without success.
Thanks for any hints. Below is the sample error message.
[Reloaded-PC:03900] [[3921,1],0] tcp_peer_send_blocking: send() to socket 13 failed: Transport endpoint is not connected (128)
[Reloaded-PC:03900] [[3921,1],0] tcp_peer_send_blocking: send() to socket 13 failed: Transport endpoint is not connected (128)
[Reloaded-PC:04676] [[3921,1],2] tcp_peer_send_blocking: send() to socket 13 failed: Transport endpoint is not connected (128)
[Reloaded-PC:04676] [[3921,1],2] tcp_peer_send_blocking: send() to socket 13 failed: Transport endpoint is not connected (128)
The problem is solved by disabling the unused network adapter in "Control Panel->Network and Internet->Network Connections".
It turned out the unused network adapter tried to get configured by DHCP and an IP address started with "169.254.X.X" was assigned to this adapter when DHCP fails. Somehow openmpi on Cygwin use that invalid IP address for establishing communication between processes.
I figured it out by looking at /tmp/openmpi-sessions-{username}/{PID of orterun}/contact.txt.
I had this same problem on Cygwin with OpenMPI 1.10.4.
Try adding "-report-uri -" to your mpirun command to see what IP address it's trying to use for connection:
mpirun -report-uri - -np 2 a.exe
It should print out a line that looks something like this:
568328192.0;tcp://192.168.10.103,169.254.247.11,0.0.0.0,0.0.0.0,0.0.0.0:55600
If the first IP address after the "tcp://" is not a current valid address for your machine, that's the problem and things are likely to break (even if the correct IP appears later in the list). Apparently ORTE is not smart enough to order the interfaces based on what is actually enabled and online.
If the wrong IP corresponds to an old/disabled interface, uninstall it (if possible) using the windows network connections control panel.
In my case, the first address was a DHCP address for an old hardware adapter I'd removed and thrown away long ago (but apparently not uninstalled in software). Windows normally hides such removed-but-not-uninstalled interfaces in the control panel, but the settings remain in the registry under:
HKLM\SYSTEM\CurrentControlSet\services\Tcpip\Parameters\Interfaces\
Search in that registry subkey for the bogus IP address and you are likely to find the problematic interface. I fixed mine by changing the IP address in that registry key to match my current static IP, but uninstalling the interface entirely would probably also work.
I had the same problem with openmpi v 1.8.8 (which is the default version of the package installed by cygwin). Manually going back to version 1.8.6 fixed the issue for me.
I just encountered this problem and in my case I had to disable the "VirtualBox Host-Only Network" adapter (I recently installed virtualbox and have not used openmpi in cygwin after that until today).
1. Open the Cygwin terminal.
mpicc --version
mpirun --version
If not execute, follow the document below and reinstall everything. Document
2. Try turning off Bluetooth and test your program again.
3. Try closing the Wifi and test your program again (you can connect to the wired internete)
4. Open C:\Windows\System32\drivers\etc\hosts
add line
127.0.0.1 localhost cygdrive wpad
and test your program again.
5. If you have a virtual network like VirtualBox or similar, turn off the control panel and test your program again.
6. If possible, uninstall VirtualBox completely. Restart your computer and test your program again.
7. Try turning off the Windows Firewall and test your program again.
The above steps solved both the "tcp_peer_send_blocking: send () to socket 12 failed: transport endpoint is not connected" error and the slowness problem in MPI for Windows 10 - Cygwin.
I am using SSH Secure Shell to connect to a server. My connection is allowed to Tunnel X11 connections but when I execute the command. The display is not showing up. I get the message:
couldn't connect to display "localhost:12.0"
I have a ssh server installed and running on my machine.
Remember: Both the client and the server have to allow X forwarding.
On the server look in /etc/ssh/sshd_config and make sure you have X11Forwarding yes. You will need to restart the service if you edit this file.
On the client look in /etc/ssh/ssh_config (your user ~/.ssh/ssh/config will override global settings, if you have created this file) and make sure you have ForwardX11 yes.
Alternatively give the -X switch when you create your client connection. e.g. ssh -X user#host
Oh and of course, your client needs to be running an X server which you have authority to use! E.g. if you connect from Windows using PuTTY it will never work, as Windows is not an X server!
I figured it out. I needed to have X-Server installed on my computer instead of SSH-Server. I installed Xming for that purpose and now everything works as it should.
I am using Cygwin X and Debian. I can forward my X session via SSH but what happens is that I seem to loose the display forwarding in the X session once in a while (from Cygwin to Linux). So i am guessing that that is an imnplementation thing with Cygwin because I never loose X11 display in the same ssh session when I use Linux to Linux.
This also happens when a X11 forwarded app tries to fork another process lets say I run Thunderbird and I click on a url inside an email. Naturally Thurderbird will try to start the default web browser but it is not doing it with Cygwin X server and here is the message I get when SSH session gives up the display for various reasons that I am not able to know.
"Error: cannot open display: localhost:10.0"
The other issue is that since the ssh gives up the display variable, I have to restart my ssh session to get it working which also kills other apps that I might be running during the ssh session.
Anyway after struggling with this for a while I am thinking that I want to be able to open my apps on another display without using ssh forwarding. I am using it internally and it is almost a closed lan so I am not worried about the security for now. I just want to be able to run the app on the Linux then see the app on the Pc that is running Cygwin.
I tried basic DISPLAY variable thing like "export DISPLAY=MY_CYGWIN_PC_IP:0.0" (on Linux Pc) but it does not work.
So I am wondering about how I can achieve this. What are the proper settings to achieve what i need?
Your direction was OK. export DISPLAY is what you want. But it is not enough.
On the target, you need to type
xhost +from.where.the.windows.are.coming.com
It gives the X server the permission to allow remote windows from this computer.
Beware, it is not really secure! A possible attacker could not only windows shown by you, but even control your mouse/keyboard. But for simple solutions, or if you can trust the remote machine and the network between you, it may be ok.
If not, there is an advanced authorization, based on preshared keys. It is named xauth. Google for xauth.
The Xorg server has an option to disable the remote windows, and there are distributions, (f.e. ubuntu!) who turn this option by default on. You can test it - if you can telnet to the tcp port 6000, it is allowed.
If you are using ssh -X, don't. Use ssh -Y
Cygwin XWin server randomly loses connection
Basically to work as old times , we need enable xdmcp on display manager and use X11 , Xwayland seems to me that doesn't work either.
sddm doesn't support xdmcp , but gdm does , you need edit /etc/gdm/custom.conf and add
[security]
DisallowTCP=false
[xdmcp]
Enable=true
xhost + ip_of_remote_computer
echo $DISPLAY (the number of the display usually :0 or :1)
after you can verify :
netstat -l | grep xdmcp
udp 0 0 0.0.0.0:xdmcp 0.0.0.0:*
lsof -i :xdmcp
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
gdm 862335 root 12u IPv4 71774686 0t0 UDP *:xdmcp
on remote host :
export DISPLAY="ip_of_server:0" (see if is 0 or other number in echo $DISPLAY on server mention above )
xclock &
References:
http://www.softpanorama.org/Xwindows/Troubleshooting/can_not_open_display.shtml
https://tldp.org/HOWTO/html_single/XDMCP-HOWTO/
https://wiki.archlinux.org/title/XDMCP