Shulou(Shulou.com)06/02 Report--

First, how to set the cloud server to prohibit public network connection:

If the cloud server wants to be unable to connect to the external network, it is only allowed to be accessed by the server of the internal network, which can be set up in the following ways.

Method 1:

Disable or uninstall the external network card. The windows system can be disabled or uninstalled directly. Linux recommends adding the command ifconfig (adapter name) down to / etc/rc.local so that it loads automatically when you boot.

Method 2:

Set up the security group of the cloud server, and add several servers in the private network to a separate security group. This security group rule deletes all the rules of the public network outbound direction and the public network inbound direction, and then the server cannot be accessed through the public network.

For external network users, it is impossible to access our Web server by accessing the IP of the intranet. The ip address of the intranet is the local area network, and the computers in the intranet access the Internet through a public gateway using the NAT (Network address Translation) protocol.

The private network IP of the cloud server can be the same in different Lans, and the private network ip cannot be used for domain name resolution. Can not be directly used for remote login of cloud servers, its main function is to communicate with other machines in the same cluster under the current account.

Second, the difference between the internal network and the external network:

1. Range size:

Local area network (LAN), compared with wide area network (WAN), mainly refers to the computer interconnection network in a small area. This "small area" can be a family, a school, a company, or a government department. Public network and external network are often mentioned in BT, that is, wide area network (WAN); private network, internal network, that is, local area network (LAN) is often mentioned in BT.

2. IP address:

Every computer (or other network device) on the WAN has one or more WAN IP addresses (or public or external network IP addresses). The WAN IP address can only be applied for after paying the fee at the ISP, and the WAN IP address cannot be repeated. Each computer (or its equipment) on the local area network (LAN) has one or more local area network IP addresses (or private or intranet IP addresses). The local area network IP addresses are assigned within the local area network, and the IP addresses of different local networks can be repeated and will not affect each other.

3. Transmission rate:

Due to the limitation of small geographical area, local area network (LAN) usually has a much higher transmission rate than wide area network (WAN). For example, the transmission rate of LAN is 10Mb, while the transmission rate of FDDI is 100Mb/s, while the backbone rate of WAN is only 64kbps or 2.048Mbps in China, and the upper limit rate for end users is usually 14.4kbps.

Source: http://www.godadly.com/news/content/325.html

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