Ok, computers have ports for applications to transfer data from the outside world into a firewall and then into a computer. Then how does firefox and internet explorer use the same port on the same computer? And why can't we use port 80 to pass all traffic from all places into the computer. So why do we need specific ports? ...
Hi, I have a java 1.4 RMI application. By using custom socket factory, I am running my RMI server in a particular port (5050). The problem is, when the RMI client application tries to communicate to RMI server from a different machine, random ports are being opened up in the client machine (Can see through TCPView.exe). Since, firewal...
Hello all, i'm running on a Dedicated server and i have two IPs Is it possible to block some ports for just one of the IPs via CSF firewall? What i mean is that i have two domains configured to two IPs let's say example1.com is on ip 1.1.1.1 and example2.com is on 1.1.1.2 how can i block some ports for IP 1.1.1.2 and still have the...
I am beginning work on an intelligent firewall but before I do that I need to understand clearly how a very basic firewall will work. Since me and my team is most comfortable in C we are going to use that. Could someone give example of a very basic firewall written in C. ...
Hi, I want to make a simple program that can restrict any communication over the internet except for some specific ip's. So that the user can eliminate any unwanted traffic. It has to be simple and the user must be able to switch it on and off on the fly. My first thought was to use Windows Firewall and set it up using C#/WPF. And it ...
How do you debug a firewall issue with your application at a customer site? Currently we have an issue where Apache and Tomcat (part of the application) throw errors that sound like the firewall is blocking our attempt to accept or bind to ports on the machine. The problem for us is we can't see what the firewall is doing, because it i...
Which of the following ports is the best one to use for a program I'm working on using a custom protocol still under development. I'm looking for one that will be accessible to virtually every host that is connected to the public internet (ie every host that can view websites can use this port). The three main options are: port 53 udp ...
I'm looking at porting an Interbase 6 / Delphi 7 application to embedded Firebird in Delphi 2007. One of the problems we have is getting our users (often quite an unskilled bunch, really - though I love them to bits, naturally) to unblock our applications in their firewall. Windows firewall itself is fairly straightforward but often they...
Apologies if this is a dumb question, I've limited network knowledge. If I sent a string to port 80 on UDP, would the server / receiving IP log it? I'm pretty sure it wouldn't in access logs, but what about firewall logs? ...
Hi We have a device with a web server running on it. From a PC, you can access web ui of the device using a web browser. This works fine when the pc and device are under same corporate network. We sell these devices to lots of customers. I am working on a tool that helps our support guys to access the web ui of the device that are runnin...
In the classic "RESTful Web Services" book (O'Reilly, ISBN 978-0-596-52926-0) it says on page 251 "Some firewalls block HTTP PUT and DELETE but not POST." Is this still true? If it's true I have to allow overloaded POST to substitute for DELETE. ...
Simple issue. I'm working on a proof-of-concept for an application with additional database connection, so I will create a WCF service to wrap around the database. Multi-user environments will get this service installed on a centralized server with a client application on their local system. These users will automatically have to deal wi...
I suspect that the corporate firewall is preventing gems from getting installed. I have HTTP_PROXY defined and I'm able to view remote gems via the following command: jruby -S gem list -r But when I go to install a gem, I get a 404: jruby -S gem install rails Is there a good workaround for resolving this issue other than maintainin...
To help customers troubleshoot VoIP, I was thinking of using www.nmap-online.com to scan their NAT router to check that their SIP client successfully punched the SIP/RTP ports open on their router. As a test, I used Nmap Online to scan my own PC which is behind a NAT router, but although UDP5060 was not used, nmap still reported it bein...
Hi guys. A company I am working with recently installed a software firewall on their server. The unfortunate thing is that that coincided with a change that I made to one of their files. But, the only change that I made was a correction to a Smarty template file path inside a script. That's all. The backup file that I made is exactl...
Following on from the general answers in this question: http://stackoverflow.com/questions/1954012/blocking-access-to-site-by-banned-ip-addresses and working on a C# ASP.NET MVC stack, how would I programmatically add IP addresses to the list of banned IP addresses on a Windows Server 2003 firewall? The use case is that the log files ...
I'm extremely excited about html5's websockets spec but I have a concern. These days everyone is operating off of some network, with routers (wired/wireless) that have built in firewalls, windows has a built in firewall too. With that in mind when the server attempts to connect back to the browser that started the websocket handshake...
I want to to create a simple client/server chat application. The idea is that when one client sends a message to the server the server informs the other clients with the change. What is the best way to do so without having to deal with firewall problems? Can it be done with web services over http? ...
I've recently moved my dev environment (VS.NET 2008 SP1 on VMWare) over to a new network, using a more restrictive firewall. During subsequent builds, the license compiler (lc.exe) took a long time to complete (several minutes). I assume it was timing out because it was not able to connect through the firewall, but I can see no evidence ...
We have a Win32 based app that uses Bonjour to advertise itself, but plain ol sockets to actually communicate. On a regular XP, Vista, or 7 system using the Windows firewall service we have no issues. We have our installer set to allow ourselves through the firewall. But if a user installs McAfee as an example, even if they click to all...