I just went to https://www.sharedrop.io/ and it says my private LAN IP address 192.168.0.3, which is correct. How can it know this? This information isn't sent out via the browser. Or is it?
I'm using Chrome, no extensions installed.
Go here and view the source - http://net.ipcalf.com/ They parse the metadata from the SDP while creating a WebRTC connection. The code is commented with links to the relevant RFCs.
This is probably how ShareDrop does it too.
Edit: ShareDrop is open source and they do this exactly the same way as mentioned above, see https://github.com/cowbell/sharedrop/blob/master/app/scripts/app/controllers/index_controller.js
Related
I have a VPN configured by ovpn in my mikrotik that already works, but whenever I connect both by android and Windows, I get the error:
ovpn,debug,error,,,,,,,,,l2tp,info,,debug,,,critical,,,,,,,,,,,,,warning duplicate packet, droppin
On console and terminal:
I have already looked for the official forum of mikrotik but neither has no clear answer or a definitive solution.
My goal is to remove this error from my terminal and from my console log.
My current setting:
OVPN SERVER:
PPP PROFILE:
#Edit:
After contacting support, I got this error message to have no impact on the VPN. Below is the email from Mikrotik Support:
Email:
"Hello,
This error message does not have any impact on the VPN connection
establishment, it simply warns you that the client sent duplicate
message which some client software (for example Windows) do.
Best regards, Emils Z."
Thank you all for your help.
I would advise that this is probably a bug in the OVPN implementation on Mikrotik's side. Please log a support ticket with them, and provide the supout.inf file as per the usual process.
Please see this link on how to make the support info file:
https://wiki.mikrotik.com/wiki/Manual:Support_Output_File
In short, open winbox, click the make support file on the left, and then go to files and download the file to your pc. Then attach this file to the support ticket.
I am a student and today for a lab, we were asked to install and use Wireshark. The installation went well, I installed the correct version, installed WinPcap, and the program started without any issues.
I was connected to the University's Wifi and as part of our lab we had to visit http://www.cas.mcmaster.ca/~rzheng/course/CAS4C03W17/Labs/INTRO-wireshark-file1.html and answer questions about the data captured in Wireshark.
Problem is, I am not getting any get or post requests, filtering by http.request.method == "GET" shows nothing, and http.request.method == "POST" shows nothing as well. Filtering by http shows the 200 OK and 304 Not Modified (if I refresh).
I was the only one in my lab who had this problem, and my instructor wasn't able to figure it out. He saved and sent me his output which has Get and Post requests so I can continue my work.
Did anyone have this problem before or have any idea on how to solve it? I can upload the saved outputs if you think it would help. Thanks!
Capture sample looks like it's filtered, since it contains only packets sent to your PC IP address. What is missing:
There is not a single outgoing packet, despite they are obviously on the net. E.g. there are "TCP acknowledge" packets received by PC in capture file, but packets sent by PC, which are acknowledged by them, aren't shown.
Not a single incoming broadcast/multicast packet. This situation is possible, but not very likely.
So there is some trouble with sniffer setup on your site. Possible explanations:
accidentally configured capture filter (don't mix with display filter)
Some interfering software is installed. Example of the same complaint
Method to determine if issue is gone: apply !(ip.dst == YOUR_IP_ADDR) display filter and check if packets output isn't empty on visiting any web page. Possible plan of troubleshooting:
check capture filter
check different network card (e.g. non-wireless connection)
check wireshark operability in pure environment (e.g. liveUSB)
try removing suspected interfering software
I build a custom mininet topology: 2 hosts with 2 switches between them:
Host1====Switch1====Switch2====Host2
After filling the flowtables with ONOS, the setup works fine. But I have trouble with handling packets that are forwarded to the SDN-Controller.
As controller I use my own onos-app.
I tried some pinging and sniffed the interfaces with tcpdump.
When one host pings the other host, the host sends an arp request. This request reaches the other host and it replies. Even the reply reaches correct the ping-host. But then... Nothing happens.
I would expect the first host to send the ping after he had received the correct arp reply. But instead it does absolutely nothing.
This even doesn't work using only one switch.
Why does the ping itself doesn't start?
Have you any idea what I did wrong?
Thank you.
R you using ONOS or RYU? It seems like you are using RYU.
If you are RYU: Do you have controller setup properly. Run the RYU using the provided controller code like simple_switch_13.py. See if that works.
If you are ONOS, have you installed features? Based on this tutorial you shuld install a feature. something like:
onos> feature:install onos-app-fwd
I don't know how you are programming the switches but for both controllers note that you should add flows for both directions.
Also, sometimes the flows have a very short lifetime that by the time packets arrive they are expired.
If none of these helped, could you provide more details.
OK. Problem solved :-D
This is what went wrong:
The onos-core itself places the default rules for ARP, IPv4 and IPv6, that redirect packets to the controller. Even if the onos-core writes such a default rule to the flowtable of the switch , it doesnt mean that all packets reach your app. In my case only the ARP-packets reached my app, not the IPv4-packets. Therefor I must add 3 lines to the "#Activate"-section of my app.
#Activate
public void activate() {
appId = coreService.registerApplication("org.onosproject.ifwd");
packetService.addProcessor(processor, PacketProcessor.ADVISOR_MAX + 2);
//***ADD THESE 3 LINES*********************************************************
TrafficSelector.Builder selector = DefaultTrafficSelector.builder();
selector.matchEthType(Ethernet.TYPE_IPV4);
packetService.requestPackets(selector.build(), PacketPriority.REACTIVE, appId);
//*****************************************************************************
}
I'm working with freeswitch and I made the connection between my server and another one, for hearing each other I used the codec G729. The issue is the next: I call them, the call is established and I can hear the other part perfectly but they can't hear me and they can see the audio packets coming to their server but they can't hear me, any idea? Thanks!
I'd start by looking at the firewall on the remote machine. libpcap will allow you to see all packets hitting the box before the firewall rules are applied, so it can be a little deceptive. So there's a good chance that the firewall is blocking the packets.
Also, you didn't specify what the other user is connecting to their server with, and how. So if they're connecting to their server from behind NAT, then you could just be experiencing the typical one-way audio issues so common with NAT scenarios. Check out http://wiki.freeswitch.org/wiki/Nat for more info.
This issue doesn't seem to be directly related to the g.729 codec or you'd have most likely gotten a 488 SIP response.
It's possible that the person on the other end isn't able to decode the the G729 stream.
What kind of phone are they using?
I would google that phone model and try a known supported codec for it.
Then I would setup your Freeswitch to encode for that codec.
If that works then it's likely an issue with the phone.
Hope this helps.
I want to send a message to everyone(broadcast) in my subnet(LAN) so as to prevent them using Internet due to repair work that's going to happen. How do i do that ? I can't use "wall" because no one is logged on some server.
I want to send a packet that opens a new Tab in web browser and displays message that stop using Internet during a certain duration.
http://en.wikipedia.org/wiki/ARP_spoofing
You might be interested in something like this. I am not sure if this will work in your LAN environment, but typically it should mess up with the entire LAN :D
you can use sockets to send a message to everyone connected in LAN, you can use java and when you want send a message to all clients, every client will see a msgbox with the information you want display....
net send command will be helpful in windows machines. Im not sure about linux.
Plz refer the following link for more Info.
http://www.cezeo.com/tips-and-tricks/net-send-command/
This is a solution shared by my senior( Hope it helps anyone who views this post). What we can do is to do DNS spoofing and redirect everyone's request to a server where you can show the required message.