UDP multicast does not work when sending from wire to wireless - networking

I implemented UDP Multicast through C++, which works very well.
but Strangely, I have a problem testing it between my laptop (wireless) and my PC (wired).
using the same network, the laptop is connected via Wi-Fi through the router, and the PC is connected via a wired LAN.
as a result of my test, if I send Multicast packets from PC to laptop, it will not be received properly.
Conversely, when a Multicast packet is send from laptop to PC, it is received well.
code used the same code, so there seems to be no coding problem.
Why is the network working like this?

Related

Transfer data between two devices on different routers on the same modem

I have two devices, a PC and a RaspberryPi, that are connected to two different routers (one has VPN, one does not), that are connected to the same modem. (See diagram). The two routers are physically separated, so it would be difficult to connect them with a cable.
I am trying to access the RaspberryPi from my PC using SSH to run programs remotely on the Pi, and have the Pi send data that the program scrapes back to my PC for processing.
My question is, is this possible? And if so, how would I be able to implement it?
Thanks
I had this working (prior to my network reconfigure).
What I did was set router A as DHCP server.
Router B was configured as not to hand out IP Addresses.
Connect router A and router B on the LAN side.
All clients went through Router A, unless the devices' IP Settings were changed. I only changed gateway to router B to have the secondary connection.

Packet Tracer cannot send pdu from lan to wireless

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I can't send pdu from pc to wireless laptop
It actually can send the PDU because u only have a network so the network between your PCs and your laptops is actually the same network. Check your IP address on your PC (it should be on the same network / subnet). If your PCs and laptops are already on the same subnet, check the port of the connected cable on the wireless router. It should be placed on ethernet / gigaethernet. But u can't connect it into internet port.
The wireless router that u are using is actually only Access Point. Because of that, it only can have a single network either on LAN or wireless.
Hope it helps!

Connect ethernet PC to other wifi connected devices (the same router)

I have a PC (Windows 10) connected to my router through an ethernet cable. I also have a few devices connected to the same router. What I would like to do is make them "see" each other. I want to transfer files from my phone to my pc and back using ES File Explorer. I want to Broadcast movies to my smart TV using apps like Wondershare.
My PC is visible for other devices but I can't seem to find it using my TV or phone. Therefore... i guess all these devices are not connected to the same "mini-network". I don't know how to call it.
What should I do?
If you are in the same subnet as the router and there are no firewall rules blocking it, you should be able to see the devices on your computer. If you go to your phone settings, search for the IP and try to ping it with the command line of your choice. If it does not work, compare the subnet mask and ip address of your devices, make sure they are in the same subnet.
On windows the command is: ipconfig on linux: ifconfig or the new form: ip addr

Wake On LAN Configuration

I am trying to configure my laptop to be able to Wake On LAN via Magic Packets. I have a magic packet sniffer and it alerts me when a magic packet has been recieved(runs on target machine). The trouble is when I try to use the external ip address instead of the internal address. I have port forwarded port 9 to my internal ip(10.0.0.x, NOTE: x is only one digit). If I use the internal ip address, it tells me that a magic packet has been received. If I try the external ip address and sending from the target machine(to itself) it receives the magic packet. If I send it through a different machine or a website, it does not work. I am connected via ethernet cable(CAT 5). I also have the "Wake on LAN" setting in my BIOS set to "ENABLED". Also, my computer is set to "Allow this device to wake the computer". Am I doing something wrong?
P.S.
The solution to the previous problem was to start the Simple TCP/IP Service in Windows.
To use Wake on LAN across the internet (=> wake on WAN), you must do one of these things :
Edit your router's ARP table so it can forward the magic pack to the target computer with its MAC address
Port forward to LAN broadcast address so the target computer will always receive any magic packet sent to your router until it is plugged to the router
Buy a router with a built-in wake on lan feature (like DD-WRT open source firmware)
Use a magic packet repeater to forward magic packets to the broadcast address. This one should be always powered on
I'm using the fourth option to wake my home computer from my work. I bought an Arduino Uno + Ethernet shield and wrote a little program to do the job (forward magic packet). I set a port forward rule into my router (Netgear DG834G) to forward UDP 9 to the Arduino IP address.
I wrote a tutorial about this on my personal website, it's in French but code is universal ^^ : http://www.finalclap.com/tuto/arduino-wake-on-lan-repeater-80/
I did some more research and it turns out that unless the router itself has a built in management and can be accessed publicly, WoL will not work behind a router. WoL will work however if you have a device already inside the network send the magic packet to the target machine. THat completely destroys the point of WoL!

IOS4 - Send data using UDP socket on Wifi

I am trying to send data using the AsyncUDPSocket class. And I can send data using the iPhone simulator over the wire to another machine that is running a simple C-coded listening server. I can also receive data over the wire using a client connected to the simulator(server). However, when I tried the same over Wifi, using the simulator, I could only send data but not receive any data.
I read on another post, that unicast data makes this possible. How can I acheive this using AsyncUDPSocket?
Thanks,
Angelo.
Ok, I figured this out. A newbie kind of thing, really.
When I set my Mac network preferences to Ethernet, I get an IP for me to communicate. However, when I turn Airport(Wi-Fi for more newbies) ON, and ethernet cable disconnected, I checked my network preferences, and sure enough my IP address was a different one.
Spoke to a friend (an ace in networking) and the thing clicked immediately: On WiFi networks a DHCP server allocates an IP address. This IP address has to be reserved, at the very least, at the DHCP server. Since my IP was not reserved, I had to change the IP address, in my udp_client.c file, recompile and run the client to connect.
BTW, I can now communicate between my iPhone and my PC using my local WiFi (office) network.
For any who might face the same problem, do not be assured that the IP address of your mchine is the same, when you switch from LAN to Wifi, and use the device mostly for WiFi reated testing. :)

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