VNC only displaying the mouse cursor but nothing else - raspberry-pi

I have a RaspberryPi with Raspbian and x11vnc installed. I can:
startx &
x11vnc -usepw -background
And then connect to the VNC Server using my Mac. However, after some event (it used to work at some point), the VNC Server only displays a black screen.
I can connect to the RPI using SSH but I can't attach a screen at the moment, because I don't have one.
How do I get the X11vnc Server to display the actual screen again?
The output when I start the server
03/02/2014 18:38:59 -usepw: found /home/pi/.vnc/passwd
03/02/2014 18:38:59 x11vnc version: 0.9.13 lastmod: 2011-08-10 pid: 5589
03/02/2014 18:38:59 XOpenDisplay("") failed.
03/02/2014 18:38:59 Trying again with XAUTHLOCALHOSTNAME=localhost ...
03/02/2014 18:38:59
03/02/2014 18:38:59 *** XOpenDisplay failed. No -display or DISPLAY.
03/02/2014 18:38:59 *** Trying ":0" in 4 seconds. Press Ctrl-C to abort.
03/02/2014 18:38:59 *** 1 2
3 4
03/02/2014 18:39:03 *** XOpenDisplay of ":0" successful.
03/02/2014 18:39:03
03/02/2014 18:39:03 Using X display :0
03/02/2014 18:39:03 rootwin: 0x43 reswin: 0xa00001 dpy: 0xe86250
03/02/2014 18:39:03
03/02/2014 18:39:03 ------------------ USEFUL INFORMATION ------------------
03/02/2014 18:39:03 X DAMAGE available on display, using it for polling hints.
03/02/2014 18:39:03 To disable this behavior use: '-noxdamage'
03/02/2014 18:39:03
03/02/2014 18:39:03 Most compositing window managers like 'compiz' or 'beryl'
03/02/2014 18:39:03 cause X DAMAGE to fail, and so you may not see any screen
03/02/2014 18:39:03 updates via VNC. Either disable 'compiz' (recommended) or
03/02/2014 18:39:03 supply the x11vnc '-noxdamage' command line option.
03/02/2014 18:39:03
03/02/2014 18:39:03 Wireframing: -wireframe mode is in effect for window moves.
03/02/2014 18:39:03 If this yields undesired behavior (poor response, painting
03/02/2014 18:39:03 errors, etc) it may be disabled:
03/02/2014 18:39:03 - use '-nowf' to disable wireframing completely.
03/02/2014 18:39:03 - use '-nowcr' to disable the Copy Rectangle after the
03/02/2014 18:39:03 moved window is released in the new position.
03/02/2014 18:39:03 Also see the -help entry for tuning parameters.
03/02/2014 18:39:03 You can press 3 Alt_L's (Left "Alt" key) in a row to
03/02/2014 18:39:03 repaint the screen, also see the -fixscreen option for
03/02/2014 18:39:03 periodic repaints.
03/02/2014 18:39:03
03/02/2014 18:39:03 XFIXES available on display, resetting cursor mode
03/02/2014 18:39:03 to: '-cursor most'.
03/02/2014 18:39:03 to disable this behavior use: '-cursor arrow'
03/02/2014 18:39:03 or '-noxfixes'.
03/02/2014 18:39:03 using XFIXES for cursor drawing.
03/02/2014 18:39:03 GrabServer control via XTEST.
03/02/2014 18:39:03
03/02/2014 18:39:03 Scroll Detection: -scrollcopyrect mode is in effect to
03/02/2014 18:39:03 use RECORD extension to try to detect scrolling windows
03/02/2014 18:39:03 (induced by either user keystroke or mouse input).
03/02/2014 18:39:03 If this yields undesired behavior (poor response, painting
03/02/2014 18:39:03 errors, etc) it may be disabled via: '-noscr'
03/02/2014 18:39:03 Also see the -help entry for tuning parameters.
03/02/2014 18:39:03 You can press 3 Alt_L's (Left "Alt" key) in a row to
03/02/2014 18:39:03 repaint the screen, also see the -fixscreen option for
03/02/2014 18:39:03 periodic repaints.
03/02/2014 18:39:03
03/02/2014 18:39:03 XKEYBOARD: number of keysyms per keycode 7 is greater
03/02/2014 18:39:03 than 4 and 51 keysyms are mapped above 4.
03/02/2014 18:39:03 Automatically switching to -xkb mode.
03/02/2014 18:39:03 If this makes the key mapping worse you can
03/02/2014 18:39:03 disable it with the "-noxkb" option.
03/02/2014 18:39:03 Also, remember "-remap DEAD" for accenting characters.
03/02/2014 18:39:03
03/02/2014 18:39:03 X FBPM extension not supported.
03/02/2014 18:39:03 X display is capable of DPMS.
03/02/2014 18:39:03 --------------------------------------------------------
03/02/2014 18:39:03
03/02/2014 18:39:03 Default visual ID: 0x21
03/02/2014 18:39:04 Read initial data from X display into framebuffer.
03/02/2014 18:39:04 initialize_screen: fb_depth/fb_bpp/fb_Bpl 16/16/2272
03/02/2014 18:39:04
03/02/2014 18:39:04 X display :0 is 16bpp depth=16 true color
03/02/2014 18:39:04
03/02/2014 18:39:04 Autoprobing TCP port
03/02/2014 18:39:04 Autoprobing selected TCP port 5900
03/02/2014 18:39:04 Autoprobing TCP6 port
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
03/02/2014 18:39:05 Failure autoprobing: Address family not supported by protocol
03/02/2014 18:39:05 listen6: socket: Address family not supported by protocol
03/02/2014 18:39:05 (Ignore the above error if this system is IPv4-only.)
03/02/2014 18:39:05 Not listening on IPv6 interface.
03/02/2014 18:39:05
03/02/2014 18:39:05 Xinerama is present and active (e.g. multi-head).
03/02/2014 18:39:05 Xinerama: number of sub-screens: 1
03/02/2014 18:39:05 Xinerama: no blackouts needed (only one sub-screen)
03/02/2014 18:39:05
03/02/2014 18:39:05 fb read rate: 362 MB/sec
03/02/2014 18:39:05 fast read: reset -wait ms to: 10
03/02/2014 18:39:05 fast read: reset -defer ms to: 10
03/02/2014 18:39:05 The X server says there are 10 mouse buttons.
03/02/2014 18:39:05 screen setup finished.
03/02/2014 18:39:05
The VNC desktop is: raspberrypi:0
PORT=5900
******************************************************************************
Have you tried the x11vnc '-ncache' VNC client-side pixel caching feature yet?
The scheme stores pixel data offscreen on the VNC viewer side for faster
retrieval. It should work with any VNC viewer. Try it by running:
x11vnc -ncache 10 ...
One can also add -ncache_cr for smooth 'copyrect' window motion.
More info: http://www.karlrunge.com/x11vnc/faq.html#faq-client-caching

I think the problem was probably caused by me starting another startx session.
I forgot that I configured my Pi to boot into the Desktop using raspi-config.
So now I start the X11vnc session as follows via an SSH terminal:
x11vnc -bg -forever -nevershare -usepw -rfbport 5900
And it works again:

Related

Can't connect to Postgresql with specific external IP

I can connect to my DigitalOcean Ubuntu 20LTS VM instant that has PostgreSQL 14 installed without issue, but I'm trying to make it more secure with only specific IPs that can connect to the database.
I heard the way to do this is to modify the /etc/postgresql/14/main/postgresql.conf file.
When I have this line, I can connect to my database without issue.
listen_addresses='0.0.0.0'
However, if I modify this line with:
listen_addresses='123.123.123.123'
I get this DataGrip error message: [08001] Connection to 111.111.111.111:12345 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
111.111.111.111:12345 is my (fake) VM's IP and port that I already set up.
123.123.123.123 is my (fake) computer's external IP that I get from here or here
Any suggestions? Is there a log I can search from that will give me a better understanding of what is going on?
Also to note, with listen_addresses='0.0.0.0', running ss -ptl gives an output of
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 4096 127.0.0.53%lo:domain 0.0.0.0:*
LISTEN 0 128 0.0.0.0:ssh 0.0.0.0:*
LISTEN 0 244 0.0.0.0:12345 0.0.0.0:*
LISTEN 0 128 [::]:ssh [::]:*
with listen_addresses='123.123.123.123', running ss -ptl gives an output of
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 4096 127.0.0.53%lo:domain 0.0.0.0:*
LISTEN 0 128 0.0.0.0:ssh 0.0.0.0:*
LISTEN 0 128 [::]:ssh [::]:*
Documentation that I used so far:
https://www.postgresql.org/docs/current/runtime-config-connection.html
https://www.postgresql.org/docs/current/auth-pg-hba-conf.html

Use RaspberryPi model B 1 (Broadcom BCM2835) with USB OTG as an slave ethernet

I'm trying to use the Broadcom BCM2835 OTG functionality to use the RPi as a Ethernet gadget in order to establish a network connection with a host (I found this is used with RPi Zero).
The OTG is supported in RPi B1 as you can see in the Broadcom BCM2835 specification.
I tried to recompiled the kernel with the module:
Device Drivers > USB support > OTG support
CONFIG_USB_OTG:
The most notable feature of USB OTG is support for a
"Dual-Role" device, which can act as either a device
or a host. The initial role is decided by the type of
plug inserted and can be changed later when two dual
role devices talk to each other.
Select this only if your board has Mini-AB/Micro-AB
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Symbol: USB_OTG [=y]
Type : boolean
Prompt: OTG support
Location:
-> Device Drivers
-> USB support (USB_SUPPORT [=y])
-> Support for Host-side USB (USB [=y])
Defined at drivers/usb/core/Kconfig:44
Depends on: USB_SUPPORT [=y] && USB [=y] && PM [=y]
I added the usb0 interface configuration to /etc/network/interfaces.
allow-hotplug usb0
mapping hotplug
script grep
map usb0
iface usb0 inet static
address 192.168.2.1
netmask 255.255.255.0
broadcast 192.168.2.255
I added line dtoverlay=dwc2 to /boot/config.tx file.
I added dwc2 and g_ether to /etc/modules.
Nothing worked. The output of ifconfig usb0 is:
usb0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.2.1 netmask 255.255.255.0 broadcast 192.168.2.255
ether ba:b9:a5:2a:b2:04 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
The host doesn't recognize any USB device when plug.
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Error setting Coturn Server on Google Compute Cloud VM instance

I am trying to setup the coturn server on a google compute cloud VM instance running ubuntu 14.04. I think this is a firewall issue but I have opened the port tcp:3478 and udp:3478 in the firewall settings. No other process is running on the 3478 port. Anyone tried setting this on gcloud?
What am I doing wrong.
$ sudo turnserver -a -v -n -r north.gov -L 35.189.173.237
0: log file opened: /var/log/turn_2564_2017-07-06.log
0:
RFC 3489/5389/5766/5780/6062/6156 STUN/TURN Server
Version Coturn-4.5.0.6 'dan Eider'
0:
Max number of open files/sockets allowed for this process: 65536
0:
Due to the open files/sockets limitation,
max supported number of TURN Sessions possible is: 32500 (approximately)
0:
==== Show him the instruments, Practical Frost: ====
0: TLS supported
0: DTLS supported
0: DTLS 1.2 supported
0: TURN/STUN ALPN supported
0: Third-party authorization (oAuth) supported
0: GCM (AEAD) supported
0: OpenSSL compile-time version: OpenSSL 1.0.2g 1 Mar 2016 (0x1000207f)
0:
0: SQLite supported, default database location is /usr/local/var/db/turndb
0: Redis is not supported
0: PostgreSQL is not supported
0: MySQL is not supported
0: MongoDB is not supported
0:
0: Default Net Engine version: 3 (UDP thread per CPU core)
=====================================================
0: Listener address to use: 35.189.173.237
0: Domain name:
0: Default realm: north.gov
0: WARNING: cannot find certificate file: turn_server_cert.pem (1)
0: WARNING: cannot start TLS and DTLS listeners because certificate file is not set properly
0: WARNING: cannot find private key file: turn_server_pkey.pem (1)
0: WARNING: cannot start TLS and DTLS listeners because private key file is not set properly
0: Relay address to use: 35.189.173.237
0: pid file created: /var/run/turnserver.pid
0: IO method (main listener thread): epoll (with changelist)
0: WARNING: I cannot support STUN CHANGE_REQUEST functionality because only one IP address is provided
0: Wait for relay ports initialization...
0: relay 35.189.173.237 initialization...
0: relay 35.189.173.237 initialization done
0: Relay ports initialization done
0: IO method (general relay thread): epoll (with changelist)
0: turn server id=1 created
bind: Cannot assign requested address
0: IO method (general relay thread): epoll (with changelist)
0: turn server id=0 created
bind: Cannot assign requested address
bind: Cannot assign requested address
0: Trying to bind fd 16 to <35.189.173.237:3478>: errno=99
Cannot bind local socket to addr: Cannot assign requested address
0: Trying to bind fd 20 to <35.189.173.237:3478>: errno=99
Cannot bind local socket to addr: Cannot assign requested address
0: Cannot bind DTLS/UDP listener socket to addr 35.189.173.237:3478
0: Trying to bind DTLS/UDP listener socket to addr 35.189.173.237:3478, again...
0: Cannot bind TLS/TCP listener socket to addr 35.189.173.237:3478
0: Trying to bind TLS/TCP listener socket to addr 35.189.173.237:3478, again...
0: Trying to bind fd 18 to <35.189.173.237:3478>: errno=99
Cannot bind local socket to addr: Cannot assign requested address
0: Cannot bind TLS/TCP listener socket to addr 35.189.173.237:3478
0: Trying to bind TLS/TCP listener socket to addr 35.189.173.237:3478, again...
bind: Cannot assign requested address
0: Trying to bind fd 20 to <35.189.173.237:3478>: errno=99
Cannot bind local socket to addr: Cannot assign requested address
0: Cannot bind DTLS/UDP listener socket to addr 35.189.173.237:3478
0: Trying to bind DTLS/UDP listener socket to addr 35.189.173.237:3478, again...
bind: Cannot assign requested address
0: Trying to bind fd 16 to <35.189.173.237:3478>: errno=99
bind: Cannot assign requested address
0: Trying to bind fd 18 to <35.189.173.237:3478>: errno=99
Cannot bind local socket to addr: Cannot assign requested address
Cannot bind local socket to addr: Cannot assign requested address
0: Cannot bind TLS/TCP listener socket to addr 35.189.173.237:3478
0: Trying to bind TLS/TCP listener socket to addr 35.189.173.237:3478, again...
0: Cannot bind TLS/TCP listener socket to addr 35.189.173.237:3478
0: Trying to bind TLS/TCP listener socket to addr 35.189.173.237:3478, again...
bind: Cannot assign requested address
0: Trying to bind fd 20 to <35.189.173.237:3478>: errno=99
Cannot bind local socket to addr: Cannot assign requested address
0: Cannot bind DTLS/UDP listener socket to addr 35.189.173.237:3478
0: Trying to bind DTLS/UDP listener socket to addr 35.189.173.237:3478, again...
bind: Cannot assign requested address
bind: Cannot assign requested address
I figured out I was using a wrong command to start the turnserver. If anyone is facing problems setting up a a coturn server on AmazaonEC2/GCloud, this really helped me a lot: https://blog.knoldus.com/2013/10/24/configure-turn-server-for-webrtc-on-amazon-ec2/

Change bound IP running on port 7077 - Apache Spark

Can Spark be configured so that instead of binding to address 127.0.1.1 for port 7077, can
instead be bound to 0.0.0.0 . In same way as port 8080 is bound :
netstat -pln
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.1.1:7077 0.0.0.0:* LISTEN 2864/java
tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN 2864/java
tcp 0 0 127.0.1.1:6066 0.0.0.0:* LISTEN 2864/java
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
udp 0 0 0.0.0.0:68 0.0.0.0:* -
udp 0 0 192.168.192.22:123 0.0.0.0:* -
udp 0 0 127.0.0.1:123 0.0.0.0:* -
udp 0 0 0.0.0.0:123 0.0.0.0:* -
udp 0 0 0.0.0.0:21415 0.0.0.0:* -
Active UNIX domain sockets (only servers)
Proto RefCnt Flags Type State I-Node PID/Program name Path
unix 2 [ ACC ] STREAM LISTENING 7195 - /var/run/dbus/system_bus_socket
unix 2 [ ACC ] SEQPACKET LISTENING 405 - /run/udev/control
Reason I'm asking this is that I'm unable to connect workers to master node and I think the issue is that the master ip is not discoverable.
Error when try to connect slave to master :
15/04/02 21:58:18 WARN Remoting: Tried to associate with unreachable remote address [akka.tcp://sparkMaster#raspberrypi:7077]. Address is now gated for 5000 ms, all messages to this address will be delivered to dead letters. Reason: Connection refused: raspberrypi/192.168.192.22:7077
15/04/02 21:58:18 INFO RemoteActorRefProvider$RemoteDeadLetterActorRef: Message [org.apache.spark.deploy.DeployMessages$RegisterWorker] from Actor[akka://sparkWorker/user/Worker#1677101765] to Actor[akka://sparkWorker/deadLetters] was not delivered. [10] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
In spark-env.sh you can set SPARK_MASTER_IP=<ip>.
A hostname would also work fine (via SPARK_STANDALONE_MASTER=<hostname>), just make sure the workers connect to exactly the same hostname as the master binds to (i.e. the spark:// address that is shown in Spark master UI).

vnc-server installed and running but not visible over the network

Unable to connect on LAN using VNCViewer to a TigerVNC-Server on Centos
My Centos 6 installation of Vino or more accurately tigervnc-server is set up and starts successfully as defined by the procedure here:
http://wiki.centos.org/HowTos/VNC-Server
I am however unable to connect to the server using the vnc-client on a W7 machine or using a java enabled browser.
I have configured a user, namely '1:mark'
After running "ss -l" to determine the port (thanks to arcyqwerty for the netstat suggestion), I determined the correct port is 5901 or 5902.
ss -l output
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 50 *:mysql *:*
LISTEN 0 5 :::vnc-server :::*
LISTEN 0 5 *:5901 *:*
LISTEN 0 128 :::41485 :::*
LISTEN 0 5 :::5902 :::*
Below is the output of my /home/mark/.vnc/log after service start
Thu Dec 5 12:09:58 2013
vncext: VNC extension running!
vncext: Listening for VNC connections on all interface(s), port 5901
vncext: created VNC server for screen 0
GNOME_KEYRING_SOCKET=/tmp/keyring-icjZAi/socket
SSH_AUTH_SOCK=/tmp/keyring-icjZAi/socket.ssh
GNOME_KEYRING_PID=7644
Failed to play sound: File or data not found
An instance of nm-applet is already running.
** Message: adding killswitch idx 2 state KILLSWITCH_STATE_SOFT_BLOCKED
** Message: killswitch 2 is KILLSWITCH_STATE_SOFT_BLOCKED
** Message: killswitches state KILLSWITCH_STATE_SOFT_BLOCKED
05/12/2013 12:10:02 PM Autoprobing TCP port in (all) network interface
05/12/2013 12:10:02 PM Listening IPv{4,6}://*:5900
05/12/2013 12:10:02 PM Listening IPv4://0.0.0.0:5900
05/12/2013 12:10:02 PM Problems in NewSocketListenTCP(), sock=-1
05/12/2013 12:10:02 PM Listening IPv{4,6}://*:5901
05/12/2013 12:10:02 PM Listening IPv4://0.0.0.0:5901
05/12/2013 12:10:02 PM Problems in NewSocketListenTCP(), sock=-1
05/12/2013 12:10:02 PM Listening IPv{4,6}://*:5902
05/12/2013 12:10:02 PM Autoprobing selected port 5902
05/12/2013 12:10:02 PM Advertising authentication type: 'VNC Authentication' (2)
05/12/2013 12:10:02 PM Advertising security type: 'VNC Authentication' (2)
** Message: killswitch 2 is KILLSWITCH_STATE_SOFT_BLOCKED
** Message: killswitches state KILLSWITCH_STATE_SOFT_BLOCKED
(polkit-gnome-authentication-agent-1:7711): GLib-GObject-WARNING **: cannot register
existing type `_PolkitError'
(polkit-gnome-authentication-agent-1:7711): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
Initializing nautilus-gdu extension
Initializing nautilus-open-terminal extension
(null): Warning no default label for /home/mark/.gvfs`
My /etc/sysconfig/vncservers contains
VNCSERVERS="1:mark"
VNCSERVERARGS[1]="-geometry 800x600"
However from the netstat it appears that ports 5900, 5901 and 5902 are involved.
Here are the results of my tests:
browsed on the host using 'localhost:5900' Result: RFB 003.007
browsed on the host using 'localhost:5901' Result: RFB 003.008. (note: user:mark)
browsed on the host using 'localhost:5902' Result: RFB 003.007
VNC'd on the host using 'localhost:5901' Result: worked.
Note: From http://www.realvnc.com/docs/rfbproto.pdf RFB represents the Remote Frame Buffer required protocol version numbers.
I tried 1,2,3 and 4 from above substituting localhost:port for the 'hosts ip':port on a network client machine and all timed-out.
The following extra steps have been taken
Turned off the firewall
Temporarily disabled SeLinux
Successfully pinged host from client on LAN.
I am also successfully running a visible httpd service from the offending host
Any pointers would be appreciated.
Make sure that the server is actually runnning (try ps or ps aux).
If that works, then try netstat to make sure it's LISTEN on the right port