Shulou(Shulou.com)05/31 Report--

This article introduces the knowledge of "how to configure the port mapping of ROS". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Purpose:

Enterprises with IPV4 public network IP need to make intranet websites, CRM,ERP and other servers accessible on the public network.

So what is port mapping (Port-Forwarding), then you need to know about NAT and NAPT.

NAT is a network address translation.

NAPT is a network address port translation.

NAT is used for address-to-address translation, such as internal network address to public network address translation. It was later found that this was useless and the quantity was far from enough. Then we explored the TCP/IP protocol, with the help of its 16bit port capacity, innovative use of NAPT technology, an IP can be expanded to 65535 ports, and finally survived a round of equipment explosion.

So what does port mapping have to do with this?

When we use the computer to surf the Internet, it is based on the port to access, the port can be reused, referred to as port reuse.

If we use port 65162 to access port 443 of the server, the router records this information (NAPT mapping table) and NAPT it and sends it out to the public network. Xxx will also send the data back to port 65162 through 443, and the router will help NAPT send it back to our computer so that we can communicate.

NAPT table of the router:

But this port is temporary. After we refresh the page, the local port will be refreshed and replaced with a different port. The original port 65162 may be waiting to be used again. In this way, the router tirelessly helps us switch back and forth, so that we can have enough ports to access the network.

In the other direction, as a server, the server's program will listen on a specific port and use the customer to visit. Then we need to permanently assign this specific port to the server to ensure that the customer can find the server through this address and port. This is port mapping.

So how is the port mapping of RouterOS implemented?

Please welcome the topology:

IP:192.168.11.252 in the intranet of the website, the port of the website is 80

Router public network IP:100.1.1.121

Win7 computer IP: 100.1.1.254

At this time, our WIN7 computer needs to access our intranet server, how to achieve it?

First of all, we need to open our port 80 to the external network through NAPT.

In RouterOS, click IP > Firewall, select NAT, and create a new rule:

Then in Action (Action)

At this time, we will permanently assign port 80 of the public network to port 80 of the intranet website.

The test results are as follows:

Why is the port not displayed? Because this is the HTTP protocol, the default is port 80. So the browser will not show your port 80, but if you change the mapped public address port to 8888, you can display your port.

Another point to note is that in the domestic ISP environment, port 80, port 8080 and port 443 cannot be used if you do not apply for the record, because in the operator's network, you do not apply for filing with the safe. These ports are closed, so we have to use other ports to replace them.

This is the end of the content of "how to configure the port mapping of ROS". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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