Setting up an Internet connection is not as easy as it seems at first glance. And it’s good that there are specialists who are engaged in such a thing. But sometimes there are critical situations when there are no masters nearby, and you have to do the tuning yourself.
What is a gateway, and where to find it?
In order to provide a stable exit from the existing local network to the World Wide Web, an Internet gateway is used. To summarize, this is a set of hardware and software that works in coordinated mode.
Using this system tool, the network administrator can control the consumption of Internet traffic, as well as restrict / add access to the Internet to users who are members of the local community.
Internet Gateway Features
The main functions of the router are not limited to total control of network traffic. In addition, the correct configuration of the Internet gateway allows you to:
- restrict access to certain resources on the Web;
- enable / disable shared proxy server;
- open full access to mail servers;
- activate shapers both locally and selectively;
- keep track of traffic on the firewall;
- work with other network applications and utilities.
In addition to the usual ones, there are specialized gateways that open up a number of additional functions for owners:
- advanced anti-virus protection;
- Advanced Snort Network Attack Detector
- confidential data blocker;
- full-fledged VPN server, which will control the Internet gateway.
Gateway Operation Principles
The operation of the gateway is not limited to any special equipment. Its installation can be performed on the following resources:
- any machine connected to the local network;
- on a separate server;
- on a virtual (cloud) server;
- as a distribution kit on a PC with a working system (Windows, Linux, etc.).
After the initial deployment of operating systems, the gateway automatically finds and recognizes all existing interfaces, both internal and external.
For reference: the internal interfaces establish communication with all PCs in the internal network of the organization, and the external ones - configure the connection with Internet providers and other unconnected networks.
At the second stage, the network interfaces are connected to the working network. The most popular are DNS, DHPS servers.
Each has its own advantages associated with small savings in traffic consumption and a large range of functions.
And at the third stage, the network administrator configures the user and protocol access policy in the local and unconnected (external) network. For this, a firewall is used. Practice shows that the Internet gateway is closed for all outside interference, except for the mail servers used. The local network is configured by providing all the privileges for users inside the network.
Linux Gateway Settings
Given that Windows, due to its high cost, is not very popular, you should pay attention to how the Internet gateway is configured on Linux. In particular, such systems are in demand for small and medium-sized enterprises.
Actually, a proven method is used to create and provide gateway functionality on a Linux system. It provides all the comfortable Internet access for 3-10 PCs connected by a network.
So, the configuration is as follows:
- It is necessary to determine the number of network interfaces (for full operation there should be two - for the local network and for the Internet).
- All subsequent actions are carried out using the command line.
The first step is to configure the routing permissions of the gateway itself, which is edited using the sysctl.conf file (located in the etc folder). There you need to make changes to the line net.ipv4.ip_forward = 1.
The second step is to configure the network interfaces that the Internet gateway uses. To do this, the following changes are made to the interfaces file located in the etc folder - iface eth0 inet static, with the source addresses specified.
The third step is the activation of the network address translation mechanism involved in the gateway to ensure a normal packet exchange between network users and the Internet. The iptables firewall is used to execute the function.
Network gateway - a small digression
Actually, network gateways are equipment or software that binds several networks that operate on different network protocols (for example, LAN and WLAN). The operation of these routers is to convert protocols for the normal exchange of data packets.
The most famous example of a network gateway is a router that provides direct PC access to the Internet. Naturally, in practice, data transfer looks a bit more complicated, but the router still performs the main functions using network services.
And to ensure the smooth operation of a large corporate network, the Internet gateway in network connections is integrated into a common hardware and software complex, which greatly facilitates the work and access to the Internet without loss of speed and quality.