This summer I am working at a computer summer camp. All the kids love playing slither.io
The kids really want to play on the same world but slither.io doesn't provide an easy way to do this and instead spreads them out through the multiple servers. I have limited networking knowledge but am somewhat familiar to working with webSockets.
What I was hoping I could do to get them on the same world was:
Have one kid connect to slither.io and enter a game.
Once they were in open the dev tools in Chrome and get the ip and port that they were connected to with bso.ip and bso.po
The other kids could then using the dev tools run
connect("ws:\\123.123.123.123:444")
with the ip and port set to whatever the first kid had.
Running connect gets them into slither.io but 90% of the time it is on a different server/ip address
Is there a way to get them all in the same world?
Connecting to the WebSocket alone is not enough to register the game to use it. Looking at the source code, there is a function forceServer, which sets the IP and Port:
function forceServer (a, b) {
sos = [];
forcing = true;
bso = {};
bso.ip = a;
bso.po = b;
bso.ac = 999;
sos.push(bso);
}
The sos array is global and used later on to connect to the WebSocket and register the game instance. The exact details are difficult to follow because it's all minified in game73gig.js, but I think this function sets everything up.
Run the following in the Console instead:
forceServer("123.123.123.123", "443");
There is a Tampermonkey snippet to inject a form element and JavaScript to do this automatically. I haven't tried it but it's called Slitherio-Plugin.
Related
I am looking for a basic thing yet I have not found not even a single good documentation on getting it done.
I want to allocate a floating IP, then associate it to a network interface of a droplet other than eth0.
The reason is I want to have the ability to very easily switch from one IP to the other with a programming language.
In a few words, I want to be able to do these two commands and both should provide a different response.
curl --interface eth0 https://icanhazip.com
curl --interface eth1 https://icanhazip.com
Also, I want to know what to do once I release the Floating IP, how do I roll back to the starting point.
All documentation I read, rely heavily on "ip route" and "route", most did not even work, some worked but replaced completely the old IP by the floating and that's not what I want, and also they did not show how to rollback the introduced configuration changes.
Please help, I spent 1 whole day now trying to get this to work for a project, and no results so far.
I guess there is no need to know DigitalOcean, how to make this work on other Cloud Providers would apply here too I think.
Update
After asking this on DigitalOcean community forum (https://www.digitalocean.com/community/questions/clear-guide-on-outbound-network-through-floating-ip), they claim that is not supported, although there may be some solutions to this if somebody can provide such a "hacky" solution I would take it too. Thanks
In the cloud (AWS. GCP etc.) ARP is emulated by the virtual network layer, meaning that only IPs assigned to VMs by the cloud platform can be resolved. Most of the L2 failover protocols do break for that reason. Even if ARP worked,the IP allocation process for these IPs (often called “floating IPs”) would not integrate with the virtual network in a standard way, so your OS can't just "grab" the IP using ARP and route the packets to itself.
I have not personally done this on Digital Ocean, but I assume that you can call the cloud's proprietary API to do this functionality if you would like to go this route.
See this link on GCP about floating IPs and their implementation. Hope this is helpful.
Here's an idea that needs to be tested:
Let's say you have Node1(10.1.1.1/24) and Node2(10.1.1.2/24)
Create a loopback interface on both VMs and set the same IP address for both like (10.2.1.1/32)
Start a heartbeat send/receive between them
When NodeA starts it automatically makes an API call to create a route for 10.2.1.1/32 and points to itself with preference 2
When NodeB starts it automatically makes an API call to create a route for 10.2.1.1/32 and points to itself with preference 1
The nodes could monitor each other to withdraw the static routes if the other fails. Ideally you would need a 3rd node to reach quorum and prevent split brain scenarios, but you get the idea right?
I recently bought a modem that supports CSD (Circuit Switched Data) calls. I put SIM card in it and I am able to make calls via AT commands. But these are always VOICE calls. I have another modem and I need to connect to it via CSD.
I know it is possible because our colleagues are using it this way to access some network.
They are using windows dial-up connection, but I guess that is just something that in the background calls the AT commands.
Nevertheless the dial-up is still giving me "Error 678: Remote computer did not respond". I have tried many settings, but still the same error. I even tried different computer and still got the same error.
So I found out that when I call CSD, then on the receiving side (if AT+CRC=1) it should display +CRING: REL ASYNC. So I setup another modem and called it and it showed +CRING: VOICE.
So how do I convince my modem to call in the REL ASYNC mode?
I already tried:
AT+IPR=115200 or AT+IPR=9600
AT+FCLASS=0 (this is default though)
AT+CSNS=4
AT+CBST=7,0,0 or AT+CBST=71,0,1
AT^SXRAT=0 (this changes the network to GSM)
But still when I do ATDNUMBERIWANTTOCALL; the receiving side shows +CRING: VOICE.
Also my mobile provider ensured me, that the CSD technology is still supported in my country and that I do not need any kind of special SIM card.
You need to remove the semicolon after the phone number in the ATD command: that semicolon is what tells the modem to make a voice call rather than CSD.
Check with your teleoperator does your sim card have separate data number.
Sometimes postpaid (and/or M2M) cards have three different numbers
1. voice
2. fax
3. data
In the end the number could be called normally like it is written in the question, but it only worked in Germany, not abroad...
I'm coding an extension for a customer, one of the requirements is that the extension also works offline because internet services are not that reliable, my customer's business can't stop but can deal with "stale" data, thats a nice tradeoff I guess.
Therefore, I want to code some kind of distributed cache as an extension to synchronize local data among the N nodes that will be connected running the same application and thus synchronize with the real database, hosted on the internet.
In order to achieve that I imagined that I would need to make a network broadcast and listen to incoming broadcasts, then every node that starts to run my application will broadcast it's IP address and become available as a new node for the distributed cache, failover is very important here.
I googled some possibilities I initially thought but none of them will work, I guess. The first was to do it just with HTTP, the second was to use Google Native Client to write C++ code that could run network code and thus do the broadcast, but it has limitations. Right now I'm thinking to use Java Applets but I don't really know if they have some limitations related to networking or if Chrome Extensions has any limitation with Java Applets.
Any ideas on how to do it? Using some of the stuff I suggested or another approach?
You could create an NPAPI extension, which would not be restricted by Chrome at all.
I have a somewhat basic understanding of network programming (and networking concepts in general) from taking a networking course in university a few years ago.
I remember being able to create a simple chat application, where the chat server is used as a central directory aware of which clients are currently online, but once a client knows another client it wants to chat with, the actual messages between them don't need to go through the server. I remember we could only test this over a bunch of LAN machines.
This C# chat program also has several comments mentioning that the program does not work over the internet: http://www.geekpedia.com/tutorial239_Csharp-Chat-Part-1---Building-the-Chat-Client.html
My question is why do these applications not work over the internet when "commercial" chat applications can. Surely, there is some way to make my computer accessible to the outer network even if its IP address is not valid outside the network of the ISP.
I see no problem with the linked-to code. The server doesn't even bind to a local address, which means it will listen for connections on all ip-addresses on the computer. There is however a comment for in the server article where the user changed the TcpListener object creation to bind to a specific address, which means clients only can connect to that specific address.
In the original server design, with using TcpListenet with only a port number, there should be nothing preventing its use on an Internet connected computer, unless there is a firewall blocking access.
Were you aware of networkComms.net and in particular the short chat example demonstrating the functionality here (It's less than 15 lines of code)? This was written specifically for people writing server-client apps in c# and given most of the problems you might come across will already have been solved and it might save you some time. This library is completely plug & play and has no issues working over the internet (as long as you can setup the necessary port forwarding where necessary).
Generally if both of your targets are behind NAT (so no true external ip addresses) and you are unable to configure port forwarding you need to look at 'TCP / UDP hole punching', quite an advanced technique.
i'm trying to get computer's state in my LAN...
thought about using QTcpSocket but it's not realy effective since port also should be inserted as:
socket->connectToHost("hostName", portNumber);
if (socket->waitForConnected(1000))
qDebug("Connected!");
can anyone demonstare me a better way to check if computer is responding ?
ping
int exitCode = QProcess::execute("ping", QStringList() << "-c1" << "hostname");
if (0 == exitCode) {
// it's alive
} else {
// it's dead
}
Arguments may vary. For example, I believe it would be ping -n 1 "hostname" on Windows. The example should work on most non-Windows versions.
Are you trying to check if your local machine is on the network or if a target machine is ?
There isn't a good cross platform way of doing this.
The nearest on qt is QNetworkInterface, and check attribute "ISup" - it's not perfect, it may be active if you have a network cable connected but just to a router, and inactive if you have a 3G modem but aren't on a call.
On Windows check InternetGetConnectedState()
One good way is just to verify that they can resolve domain names using QHostInfo. If they can then they likely have internet access:
QHostInfo::lookupHost("www.kde.org", this, SLOT(lookedUp(QHostInfo)));
Of course, you could just try to connect to the host as well, which is even better proof that everything is working correctly. I would do it asynchronously rather than synchronously, but it's truly the best test.