Describes the principle of Router Access to the Internet in detail.

In the access network mode, vro access to the Internet is currently one of the most common methods. Currently, there are many vro access methods, and the routing technology is gradually improving and upgrading, here we mainly introduce the principle of connecting routers to the Internet and proxy servers. For small user groups or home users to access the Internet, using proxy servers to access the Internet through dial-up or ADSL is a cheap and practical method. For small and medium-sized enterprises, routers can be used to access the Internet.

How proxy servers access the Internet

Currently, all proxy servers are installed in a computer on the LAN in the form of software. The computer has an egress to access the Internet, the access method can be the 10/100 M Ethernet interface, ISDN, PSTN, or ADSL Of the man. The other Ethernet interface is generally interconnected with the internal lan. Due to the lack of valid IP addresses, an internal local area network generally uses illegal IP addresses. These IP addresses cannot be used as the source address of IP packets to access the external network. When a computer in the LAN needs to access the external network, the access request of the computer is intercepted by the proxy server. The proxy server searches for the local cache. If the requested data is on the WWW page, you can find it, the data is directly sent to the computer that sends the request in the local area network. Otherwise, the proxy server accesses the external network to obtain the corresponding data and caches the data, at the same time, the data is sent to the requesting computer. However, the data in the proxy server cache must be constantly updated.

Connect a vro to the Internet

When using a vro to access the Internet, you can use NAT if a valid IP address is missing.) address translation technology enables internal network access to external networks. When a router receives an IP packet from a computer in the internal network that accesses the external network, it converts the illegal IP addresses into valid IP addresses and uses them as the source addresses of IP packets to access the external network, when the returned data packet passes through the router, the destination address of the data packet is converted to the Host IP address in the corresponding LAN, and the data packet is sent to the corresponding host, to access the Internet. These functions are actually part of NAT network address translation.

In addition to NAT, vrouters also use vro technology to access the Internet, mainly based on the source and target IP addresses and port filtering firewall technology. Through the firewall technology, the internal LAN can be protected from external attacks to a certain extent, playing a certain security role.

Select two access methods for comparison

In general, vro Access provides more benefits based on the following features. Vro Access provides powerful firewall and VPN functions. There are a variety of access methods. DDN and frame relay can be used. The overall network performance is better than that of the proxy server. The proxy server is installed on the computer, because the computer does not specifically process IP packets, so the performance is not very good. You can easily publish WWW information. It is impossible to use the proxy server to establish a WWW website and provide WWW information to external sites. The reason is that the WWW server requires a valid IP address or maps the illegal IP address of the WWW server to a valid IP address through NAT. At the same time, sufficient capability is required to process external data requests. In this case, you can select a vro.

The overall investment is not very high. When a proxy server is used, for networks with many nodes in the LAN, because the computer dedicated to the proxy server cannot handle other tasks, otherwise the network access to the outside will be inferior), in contrast, the difference between investing in a vro and investing in proxy server software and adding a computer is not great.