Some common problems after installing firewalls and solutions

As we all know, the purpose of Firewall is to block communications to other computers. Unfortunately, sometimes it blocks the communication you want. This article will help you solve those problems.

To handle firewall issues, you need to know about ports, because they will be covered a lot below. A port is a number that a program on a computer uses to identify a program on another computer while trying to communicate. Comparing figuratively, your computer is a room, a firewall is a large wall on which there are many numbered ports, each program corresponds to one port and is only allowed through the gate when the firewall opens that port. .

Problem: some programs may not work well after a firewall

Solution : Some programs on other computers may not work well after the network has a firewall system because for example some online games, texting programs, etc. So how to open The ports in Windows XP Internet Connection Firewall, the following will guide you to open the ports in Windows XP manually.

Open the port in Windows XP Internet Connection Firewall

After turning on the Internet Connection Firewall, some game programs and some other application programs on your Windows XP computer may not work. So how to fix this?

In order to work well, some applications and game programs must get information over a network connection. This information enters your computer via an inbound gateway. Your computer must open inbound support ports for that application, while Internet Connection Firewall (ICF) may allow this information to pass. The following is a list of applications and games that are often used with the corresponding port number, which requires you to open these ports for the program to work properly. The following section will guide you step by step to open the port in Internet Connection Firewall.

Steps to perform port opening in ICF:

1. Click Start, click Control Panel, click Network and Internet Connection, and then click Network Connections.

2. If you have a dial-up Internet connection, under Dial-up, click the connection you use to connect to the Internet. If you have a cable modem or digital subscriber line (DSL), under LAN or High-Speed ​​Internet, click on the connection you use to connect to the Internet.

3. Under Network Tasks, click Change settings of this connection.

Select 1 connection

4. On the Advanced tab , make sure you have selected the Protect my computer and network by limiting or preventing access to this computer from the Internet checkbox.

5. Click Settings.


6. On the Services tab, click Add.

On the Services tab, click Add

7. In the Description of service , type the name of the service you want to open the port. For example: Windows Messenger file transfer. Should choose a meaningful name to help you easily remember the service and port number. You can use any name you want.

8. In the Name box or IP address of the computer hosting this service on your network , type 127.0.0.1.

9. In the External Port number box for this service and Internal Port number for this service , enter the port number (same number for both boxes). To find the port number, look at the list above, check the documentation that came with the program or the ways introduced to you.

10. Select TCP or UDP , and then click OK.

Enter the Service Settings service settings

11. Repeat the above steps for the ports you need to open.

To find the port number of the programs, follow these instructions:

+ Check the manufacturer's documentation that came with that program.
+ Find on the manufacturer's Web site about that program.

+ Find information on the Internet about that program. There are many sites that provide very useful information for you.
+ Test on networking sites such as Practically Networked http://www.practicallynetworked.com/sharing/app_port_list.htm to find information about port numbers.

Note : Opening ports in ICF can create dangers for you. Just open the port when you really need to open it. In addition to opening ports on your computer, you need to know how to open the same router, wireless access point, or computer running Internet Connection Sharing. The only other thing is that you will also need to determine which computers run which application programs to add the port number.

Some devices allow the use of a computer's name while others require an IP address. The instructional materials included with the device will tell you what you need and how to find them. If you use Internet Connection Sharing, you open the port similar to the way you do it on the computer with Internet Connection Firewall except you also give the name of the computer running the application to the Name or IP address section.

Problem: Failed to perform File sharing after using ICF

Solution : On every computer you want to share files, you need to open the following ports:

- UDP ports: 137, 138, and 445
- TCP port: 139 and 445

Of course, you need to open the ports on the connection you are sharing with Internet Connection Sharing, or on the broadband router (broadband router) and wireless access point.

Problem: IM (Instant messaging) does not allow file transfers

Solution : Some IM programs do not always use the same default port number for file transfer. Fortunately, most allow configuration to do so. You should use Help programs to know how to set them up. Next, take 10 numbers in the range between 50000 and 60000 and configure the IM program to always allow the use of these ports. Finally configure the firewall on your computer and device that connects to the network to the Internet (broadband router, wireless access point, or Internet Connection Sharing computer) with those ports.

Attention

- If you use 10 ports for each program on each computer on your network, then there will be no conflicts with file sharing.

- If you need to exchange more than 10 files at once with a special application, and that application supports that then you need to open more than 10 ports. Otherwise, if you need less, open the port number less.