Cannot connect to headless virtualbox-ose: rfbProcessClientProtocolVersion: not a valid RFB client - virtualbox

I've set up a headless virtualbox-ose on a FreeBSD-10 server. Everything looks normal, but I cannot connect to it using RDP. On a Mac running Yosemite, no matter which client I've tried, the server complains that it is not a valid RFB client:
$ VBoxHeadless --startvm testvm
Oracle VM VirtualBox Headless Interface 4.3.16_OSE
(C) 2008-2014 Oracle Corporation
All rights reserved.
07/11/2014 00:15:42 Listening for VNC connections on TCP port 3389
07/11/2014 00:15:42 Listening for VNC connections on TCP6 port 5900
VRDE server is listening on port 5901.
07/11/2014 00:16:28 other clients:
07/11/2014 00:16:28 rfbProcessClientProtocolVersion: not a valid RFB client:
07/11/2014 00:16:28 Client 192.168.1.2 gone
07/11/2014 00:16:28 Statistics events Transmit/ RawEquiv ( saved)
07/11/2014 00:16:28 TOTALS : 0 | 0/ 0 ( 0.0%)
07/11/2014 00:16:28 Statistics events Received/ RawEquiv ( saved)
07/11/2014 00:16:28 TOTALS : 0 | 0/ 0 ( 0.0%)
I've tried rdesktop from a fresh MacPorts, and also Microsoft Remote Desktop, fresh from AppStore.
Any ideas?

It seems that even though the documentation claims it is RDP, it is not. At least not the OSE version. It is plain VNC, even for VirtualBox 4.3.
Connecting with a VNC client, like vnc from macports, seems to do the job.

Related

Could not connect to TCP port: Connection refused when trying to open Expo app on Android Emulator in WSL2

I've been following this guide https://medium.com/#pellea/using-adb-with-wsl2-7aebbb070a47 and so far have gotten to the point where WSL2 can see the emulator(s) running on Windows through Android Studios -> AVD manager. For example, on both Windows and WSL2, adb devices correctly shows:
List of devices attached
emulator-5554 device
However, when I go to my expo app and try to launch the Android emulator, I get the following error message:
Couldn't start project on Android: could not connect to TCP port 5554: Connection refused
This is after I've tried the following:
exporting ADB_SERVER_SOCKET=tcp:<MY IP>:5037 in my WSL2 profile(s)
Unblocking WSL2 vEthernet connections from my Windows firewall via (from the above link)
Set-NetFirewallProfile -DisabledInterfaceAliases "vEthernet (WSL)"
I've portforwarded 5554 from Windows to WSL2, as well as 5037 (from 0.0.0.0 to 127.0.0.1):
$WSL_CLIENT = bash.exe -c "ip addr show eth0 | grep -oP '(?<=inet\s)\d+(\.\d+){3}'";
$WSL_CLIENT -match '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}';
$WSL_CLIENT = $matches[0];
iex "netsh interface portproxy add v4tov4 listenport=5554 listenaddress=127.0.0.1 connectport=5554 connectaddress=$WSL_CLIENT"
The ports are as follows:
netsh interface portproxy show all
Listen on ipv4: Connect to ipv4:
Address Port Address Port
--------------- ---------- --------------- ----------
127.0.0.1 8081 172.25.38.171 8081
0.0.0.0 5037 127.0.0.1 5037
127.0.0.1 5554 172.29.149.0 5554
Just had the same issue with Expo.
Here is what fixed it for me:
Check for a process that uses port 5555 (Terminal)
netstat -ano | findstr 5555
Kill the process using its ID (PowerShell)
Stop-Process -ID [PROCESS_ID] -Force
Then it started working.
I had the exact same problem, but with a different setup (using Expo with the Metro bundler on a Mac). I worked around it by trying different virtual device images. Maybe the same can help you.
The virtual device that works with me so far is the one selected in this screenshot: https://i.stack.imgur.com/CFTJ0.png. The other two in the screenshot have the same problem. I don't really know the actual reason, must be something with port access with those other emulated devices.
Image details:
Name: 4 WVGA (Nexus S) API 29
API: 29
Target: Android 10.0 (Google APIs)
CPU/ABI (x86)
I'm sure other images work as well (or configuring the others somehow), i just haven't tried many more because it takes so long and they're so big.
Did you try to map port 5554 to Windows IP instead? (or localhost). The Android emulator is running on Windows, not WSL2, so the port proxy should be from WSL2 to Windows, not backwards.
Have you already solved it in another manner?

nmap reports closed port Centos 7 while a pid is running on this port

On a CentOS Linux 7 machine, I have a web app served on port 1314
$ netstat -anp | grep 1314
tcp 0 0 127.0.0.1:1314 0.0.0.0:* LISTEN 1464/hugo
tcp 0 0 127.0.0.1:60770 127.0.0.1:1314 TIME_WAIT -
and I can curl it locally.
I opened port 1314:
iptables-save | grep 1314
-A IN_public_allow -p tcp -m tcp --dport 1314 -m conntrack --ctstate NEW,UNTRACKED -j ACCEPT
I checked with nmap locally:
PORT STATE SERVICE
1314/tcp open pdps
Everything seems fine.
Now if I try to curl the web app from another machine I get connection refused.
When I try nmap from the remote machine:
PORT STATE SERVICE
1314/tcp closed pdps
So the firewall doesn't block the port, but it looks like there is no one listening on port 1314...
But we know that the web app is running on this endpoint so what is going on??
Having a process listening to a port (and that port is open and properly configured) is not enough to enable remote communication. The local address needs to be on the same network as the remote address too!
Here, on the netstat printout, we can see that the local address is localhost (127.0.0.1 or ::1). Localhost is obviously not on the same network as the remote machine I was using to curl my web app. This explains also why nmap was reporting a closed port (meaning that nothing was listening on the local end).
Note: to listen to all the network interfaces, the local address should be 0.0.0.0 or :::.

Which VCenter Server Applience 5.5 service should be running on 443/tcp port?

I get error 'Connection refused' when try to connect from vSphere Client and web client.
I check output of command netstat -tnpl and not see 443 port in listening ports.
Which VCenter Server Applience 5.5 service should be running on 443/tcp port?
I was able to start the service running on port 443. This service is vmware-vpxd:
$ netstat -tnpl | grep :443
tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 4780/vpxd
tcp 0 0 :::443 :::* LISTEN 4780/vpxd
In my case, i got error when vpxd started: "vpxd failed to initialize"
The problem was solved updade VCenter Server Applience, as described in the article https://kb.vmware.com/s/article/2031331
A similar problem was found in the blog:
https://blog.robinfourdeux.com/vcenter-5-1b-waiting-for-vpxd-to-initialize-failed/

Slamdata Issue in Ubuntu (14.04.3 LTS) AWS Bitnami instance

There isn't any error on installation and on startup I get the below message :
Server started listening on port 20223
Failed to open browser, please navigate to http://localhost:20223/
But the server is instance is not reachable # http://localhost:20223/ or
http://localhost:20223/slamdata/index.html
netstat -pnlt show the server is up & listening to port
tcp6 0 0 :::20223 :::* LISTEN 24564/java
any help ?
This was initially caused by a threading issue that was identified and resolved. If a user's virtual (or physical) environment had only one CPU available then the Scalaz executor might hang. It should not matter how many CPUs a server has now. See here for SD-1574 in JIRA.
Recent versions of SlamData (i.e. late April 2016 and newer) do not have this problem.

Can't communicate on open port between terminal sessions on Amazon instance

I realise that the firewall should not block traffic moving between terminal sessions on the same server, but I have included detail of my firewall here as it might be related somehow. The crux of this problem is "What linux/AWS setting could be stopping me from communicating on a port on the same instance"
I have an amazon instance (not build by me) running Debian. I am trying to get an email relay running, but that question is in another post. For starters, I just want to make sure that a port is open. The way I do this on other servers is, I make sure the firewall is not blocking the port, and then get netcat to listen on that port. So, for my instance I went to AWS security management and opened port 2525 both UDP and TCP
nothing is blocked outbound
and checked the local firewall
root#lamp # iptables-save
# Generated by iptables-save v1.4.14 on Sun Feb 28 10:36:57 2016
*nat
:PREROUTING ACCEPT [727933:41936189]
:INPUT ACCEPT [727933:41936189]
:OUTPUT ACCEPT [4341889:262878645]
:POSTROUTING ACCEPT [4341889:262878645]
COMMIT
# Completed on Sun Feb 28 10:36:57 2016
Then I ran netcat to listen on port 2525
root#lamp # nc -l 2525
logged on via a different terminal session to the same server
root#lamp /home/www# nc localhost 2525
localhost [127.0.0.1] 2525 (?) : Connection refused
root#lamp /home/www# netstat -anp | grep 2525
root#lamp /home/www# telnet localhost 2525
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
I try this on my ubuntu laptop or on my rackspace instance, the nc command should get me a kind of chat session which I terminate with a CTRL^D.
I am not too familiar with the way Amazon do things, so I guess I am missing some AWS web interface, but what confuses me is I would expect all traffic to be free to travel between different sessions on the same localhost. Any light that could be shed on allowing traffic on this port would be appreciated.
AWS Security Groups wouldn't be getting involved here in terms of opening + connecting to the server locally.
It's only relevant when trying to connect to and from other servers.
I suspect your issue is a Linux configuration issue, but of what flavour I do not know.