I'm trying to run a socket connection from my iOS app to a bespoke server.
The iOS communicates via UDP to the server on port 12345. The request needs to come from socket 54321 on the device.
How do I open up a socket connection on iOS that communicates to a server on one port but listens via a different port.
I have followed the example on:
https://www.raywenderlich.com/3932/networking-tutorial-for-ios-how-to-create-a-socket-based-iphone-app-and-server
But this does not cover the local port
I have also looked at the documentation on https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/NetworkingTopics/Articles/UsingSocketsandSocketStreams.html but I am finding it unclear due to my limited knowledge of socket connections.
I am currently attempting to use https://github.com/robbiehanson/CocoaAsyncSocket/wiki/Reference_GCDAsyncSocket
But I don't seem to be able to control the local port.
Thanks in advance
Normally you don't care about the sending socket, but when you create your AsyncUDPSocket you can use bindToPort: to set its port. Then use sendData:toHost:port:timeout:tag: to send the data
Related
I have a network application environment of 7 applications communicating with eachother through UDP and TCP. All of them using either the machine's local network IP or 127.0.0.1 (localhost) to listen on ports or connecting to eachother.
All these applications are running on a single test machine.
I want to analyze precisely how each application communicate with the others so I tried Wireshark and Netmon. However both Wireshark and Netmon don't show me any of the packets sent or received by any of these applications.
What can I do to analyze this environment? Does Wireshark or Netmon able to analyze that? Is there a problem tracking packets using same source and destination IP?
what interface did you select in Wireshark for capturing traffic?
For your case, I think you should select "Adapter for loopback traffic" in Wireshark.
It will capture loopback communication for your locally hosted application.
I am using Windows 10 with IIS 10.0
I am publishing website on IIS and I need to reach it with public ip.
What I did;
* Port forwarding through router
* Adding DMZ with my local IP
* Turning off firewall
* Adding port to firewall inbound rules with allow edge traversal
I can connect with internal IP like 192.168.1.75:81
I get "System.Net.Sockets.SocketException A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond from [MYPUBLICIP]" when I try to reach it like MYPUBLICIP:81
What are the possible scenarios that blocks to port?
Thanks.
As far as I know, the error message means there is no server listening at specified ip/port that you are trying to connect to.
In my opinion, you should firstly make sure your client machine could access your server by using this MYPUBLICIP address.
Then I suggest you could try to make sure the port 81 is your IIS web application port.
Besides, I suggest you could try to open your event viewer to find out the details error message.
I have followed the instructions to setup the CitusData Single Cluster using Docker.
When I try to use this with Laravel then this does not work and this throws for Connection Refused.
Any idea to resolve this?
I do not have experience on Laravel, but here is an idea: Make sure that you are using the TCP socket and not the Unix domain socket.
The TCP port (5432 by default) is exposed on the container but not the Unix domain socket. When running the database and the application on the same instance, your application may be trying to use the Unix domain socket because:
it is slightly advantageous to use the Unix Domain Sockets as they do not need the three-way handshakes
and they are slightly faster because of this
I currently have a Firebird 2.5 database at a client premises, installed on a Windows 7 Pro machine (32 bit), that has multiple stations in their local network that can connect to the database, along with the local machine being able to connect with our application and IBExpert.
However, for some of our software packages, a remote connection is required (outside of the local network). This previously was working but no longer works.
When I connect with FlameRobin from my office (I'm located in a different city / different network), I receive the following error message:
IBPP::SQLException
Context: Database::Connect
Message: isc_attach_database failed
SQL Message: -923
Connection not established
Engine Code : 335544421
Engine Message :
connection rejected by remote interface.
Performing this connection attempt with IBExpert, both from my office and from other external networks fail with a same message.
However, I am getting TCP/IP communication from what I can see. Here are the details of my troubleshooting steps for the last week:
Originally, I was receiving the following error when connecting from outside the network:
"Connection not established
Connection refused by remote interface"
Since that time, we have done a restart of the router and now have the current "connection rejected by remote interface." error message.
I can telnet to the public IP through port 3050 from my office and other outside networks.
I tested port 3050 on sites like YouGetSignal.com or CanYouSeeMe.org and they appear as open.
Other ports that we communicate on publicly are open and communicating.
The site has Kaspersky antivirus installed but all tests to connect via IBExpert while Kaspersky was in sleep mode behaved the same.
Installation of Firebird 2.5 to another workstation in the same local network, pointing to port 3051 (both in Firebird.conf and in the Windows Firewall and Router) show up as being open through Telnet and CanYouSeeMe.org but again, cannot be communicated on from outside via port 3051.
IBExpert works from a workstation in the network to the server
The server currently has no entry for RemoteBindAddress in the Firebird.conf
Wireshark shows that when a connecting from outside, there are packets coming through.
The TCP/IP test in IBexpert under Communication Diagnostics for the public IP as the host and the Service show the following Test Results:
Attempt connecting to XX.YY.ZZ.AAA.
Socket for connection obtained.
Found service 'GDS_DB' at port '3050'
Connection established to host 'XX.YY.ZZ.AAA',
on port 3050.
TCP/IP Communication Test Passed!
Database path, username, and password have all been checked multiple times.
locally on the server, I've changed security of the database.FDB and the security2.FDB to have Everyone, Full Control
At this point, we have a scheduled restart of the ISP's modem happening soon, although the fact that we have full TCP/IP communication over the port makes me doubtful that this is the issue.
If anyone can lead me down any recommended next steps to debug or to any tools that are available to help in this situation, that would be greatly appreciated.
This turns out to be a networking issue. We performed the following tests:
We performed a power cycle on the ISP's modem which showed no change in behavior
We connected a laptop directly to the ISP's modem but couldn't communicate to FB even with proper port forwarding rules in place on the machine and firewall.
We ran wireshark on both sides and on connection attempts, we found many attempts to connect with retransmissions that failed.
The technical team at the client side decided to install a VPN capable router and now we're good to go. From what we found there may be some kind of ISP blocking occurring as many of the tech teams remote services were failing to connect with similar behavior.
Hopefully this post helps people in the future with remote connectivity debugging, and all of the places you can look at when you're running into this problem.
I am building a basic client server application in delphi indy 10 ;
I have set sever app with local ip and a specific port, and i set client with public
IP to client host when i am testing the application the following error i got
here
I am testing both client and server app in same machine (as i had no other option),will this cause error.
You can absolutely run a TCP client and server on the same computer.
Only one application can listen on a given port at a time, but (virtually) any number of clients can connect to that server, even from the same machine.
Did you find your router settings from the previous question?