I'm working in an organization that blocks outbound NTP connections for security reasons. We have a local NTP server, but for all my searching I've been unable to find a way to configure the IOT-Devkit to connect to it. I understand why it's desirable to sync time with the IOTHub, but it's simply not an option for us.
Is there a way to configure the device to use a local NTP server?
We have solved this issue internally by making alterations to our DNS to resolve to our local NTP server.
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I was curious on why a client cannot directly to a machine running webrtc server but can do that via turn server. Both turn & webrtc are in same VPC of AWS.
Could be a lot of things.
Assuming you have the TURN configuration file correct, and as you are noting both AWS instances have public IPs, then it's possible that on the instance with the TURN server, you do not have all the firewall ports opened needed related to the TURN server: https://stackoverflow.com/a/59212004/8201657
Or, maybe it's a DNS issue and the domain of your TURN server is unknown to your peer, so it is not able to access it.
Or, maybe you are attempting to connect via WebRTC but not securely. WebRTC requires a secure connnection (https).
I have a Google Compute Engine Instance and have an ASP.NET Core application deployed to it. Within that application, I run
WebSocketServer server = new WebSocketServer("ws://0.0.0.0:2001");
To start a websocket server on port 2001. However, when I try and start a websocket connection to this port (m.y.i.p:2001), it times out. I don't understand why since the VM is tagged with the same network tag for ingress and egress that I created allowing access to all ports. If not the firewall, where else could I investigate?
For anyone else that seems to encounter a similar issue with opening a port on a VM running Windows Server (I was using the 2016 edition), I fixed it by remote desktoping into the machine and disabling its firewall. I had to do this even though I had made Compute Engine firewall exceptions. If anyone wants to clarify, I am assuming it's better to handle all firewall related things in GCP rather than having the internal firewall of the VM itself as well since there is likely to be conflict?
Is it possible (or any hack) to configure multiple stun/turn servers on the WebRtcEndpoint.conf.ini or through our signaling servers? So that if one stun fails it falls back to another? If the feature is not available what would be the closest solution?
I am not sure if I am looking into the right location - I've seen that WebRtcEndpoint has methods for- getStunServerPort()/getStunServerAddress(). So a possible client side configuration?
Reason - We've been using kurento media server (6.0) and elasticRTC 6.5 (For the future development) on an AWS vpc. It was working fine by using one of the publicly available STUN servers. Suddenly it stopped working and we figured out the STUN server was not working anymore. So we switched to Google stun and it started working normally
I would suggest, instead of using a globally configured IP in WebRtcEndpoint.conf.ini, to use the methods that you mention in the WebRtcEndpoint. That way, you can use a CNAME and resolve the IP every now and then. You might have a separate scheduled task that checks the STUN server to see if it's still available, and then refresh it when it is no longer valid.
I want to install a number of raspberry pis at remote locations and be able to log in to them remotely. (Will begin with 30-40 boxes and hopefully grow to 1000 individual raspberry pis soon.)
I need to be able to remotely manage these boxes. Going the easier route, forwarding a port on the router and setting a DHCP reservation, requires either IT support from the company we'll be doing the install for (many of which don't have IT), or it will require one of our IT people physically installing each box.
My tentative solution is to have each box create a reverse SSH tunnel to our server. My question is: How feasible would this be? How easy would it be to manage that many connections? Would it be an issue for a small local server to have 1000+ concurrent SSH connections? Is there an easier solution to this problem?
My end goal is to be able to ship someone a box, have them plug it in, and be able to access it.
Thanks,
w
An alternate solution would be to:
Install OpenVPN server on your server machine. How to install OpenVPN Server on the PI. Additionally, add firewall rules that block everything but traffic directed for the client's ssh and other services ports (if desired), from administrating machine(s).
Run OpenVPN clients on your Raspberry PI client machines. They will connect back to your VPN server. On a side note, the VPN server and administrating machine(s) need not be the same machine if resources are limited on the VPN server. How to install OpenVPN on the client Raspberry PIs.
SSH from administrating machine(s) to each client machine. Optionally, you could use RSA authentication to simplify authentication.
Benefits include encryption for the tunnel including ssh encryption for administrating, as well as being able to monitor other services on their respective ports.
I made a WebApp to manage this exact same setting in about 60 minutes with my java web template. All I can share are some scripts that I use to list the connection and info about them. You can use those to build your own app, it is really simple to display this in some fancy way in a fast web.
Take a look at my scripts: https://unix.stackexchange.com/a/625771/332669
Those will allow you to get the listening port, as well as the public IPs they're binded from. With that you can easilly plan a system where everything is easilly identificable with a simple BBDD.
You might find this docker container useful https://hub.docker.com/r/logicethos/revssh/
I would like to ask, i have a non-public IP, behind NAT. I would like to access to my home synology server from internet, but i cannot use ssh tunnel.
Is any working "how-to" tutorial about installing service like Hamachi or LogMeIn on Synology NAS server?
Thanks for any advice.
I found these resources, but without luck.
https://secure.logmein.com/labs/#HamachiforLinux
http://forum.synology.com/enu/viewtopic.php?f=143&t=30669
I am sure that Hamachi could be used for the VPN, and that can be used without port mapping, setting DMZ, without knowing the "real" (non-VPN) IP Address, etc. Hamachi can also be installed on Linux, so if you muck around enough, you can probably get it to work on DSM, however...
Given that Synology has a System called QuickConnect that allows you to connect to your NAS from outside via the web using HTTPS under pretty much all conditions, you may not need the VPN support, unless you are hoping for a remote command line.