Fast integration of DHCP and DNS services in Linux Networks

Article Title: rapid integration of DHCP and DNS services in Linux networks. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.

In daily network maintenance, especially on campus network maintenance, Managing IP addresses of hundreds of machines is a pain point for system administrators. Reality 1: the Internet connection of the campus network adopts the proxy server or router mode. To ensure normal Internet access for each workstation, you must add gateway settings on each client. Scenario 2, the campus network is generally released on the Intranet and Internet. For the convenience of computer access between teachers and students in the school, domain name resolution is required (for example, www.mycollege.edu.cn is used in a school, external www.mycollege.com), so you need to add the internal DNS server settings on each client computer.

Generally, the campus network provides DHCP and DNS services. DHCP is a Dynamic Host Configuration Protocol. The DHCP Service allows the workstation to connect to the network and automatically obtain an IP address. DHCP is useful in fast sending customer network configurations. When configuring the customer system, the administrator can select DHCP without entering the IP address, subnet mask, gateway, or DNS server. The customer retrieves the information from the DHCP server. DHCP is also useful when administrators want to change a large number of system IP addresses. Instead of resetting all systems, the Administrator only needs to edit a DHCP configuration file on the server to obtain the new IP address set. If the DNS server of an organization changes, this change only needs to be performed on the DHCP server rather than on the DHCP client. Once the customer's network is restarted (or the customer rebooted the system), the change takes effect. In addition, if DHCP is configured for a portable computer or any type of removable computer, as long as each office has a DHCP server that allows it to connect to the Internet, it can be freely moved between offices without reconfiguration.

The DNS server is mainly used for parsing between the primary IP address and the host name. Generally, Internet service providers (ISPs) of our campus network, such as China Telecom, provide DNS servers. We can also provide our own DNS servers on the campus network, it is used to resolve the IP address cache from the host in our network to the isp dns server. So how do computers on the Intranet parse each other? The DNS server of the ISP certainly does not have a list of our Intranet computer hosts. Most DNS servers cannot do this either. Unless we dynamically update the ips dns server list or use static IP addresses, WINDOWS can use the NBNS protocol (NetBIOS Name Server (NBNS = NetBIOS Name Service) the Protocol is part of the NetBIOS (NetBT) protocol family on TCP/IP. It provides the Host Name and Address ing method on the network accessed Based on NetBIOS name .). If a large number of UNIX/LINUX Hosts exist in our campus network, these UNIX/LINUX Hosts cannot be parsed from each other, because UNIX/LINUX does not support the NBNS protocol, the IP addresses of each UNIX/LINUX host are also dynamically allocated. Generally, the DNS server can only parse external URLs or static IP addresses. Unless we dynamically update or use static IP addresses, we have to set up our own DNS server on the campus network to solve this problem, this allows UNIX/LINUX Hosts in the campus network to parse each other and access internal URLs. The best solution is to integrate the DHCP and DNS services of the LINUX server so that the two can maintain data synchronization at any time, in this way, the UNIX/LINUX Hosts under the dynamic IP address in the Intranet cannot parse and access each other.

It is not difficult to add a gateway and DNS resolution address to each client at one time. However, the problem is that the address of each server that provides the service cannot be changed. Otherwise, you need to adjust the gateway or internal DNS resolution address for any reason. Can we fix all these services on one machine? In fact, the DHCP (Dynamic Host Configuration Protocol) service we usually use has the client gateway configuration and DNS Service pointing function. We usually only pay attention to the DHCP Dynamic Address allocation function, while ignoring other services.

Based on the above problems, we need such a solution. On the campus network, there is a normal LINUX-based DHCP server with the IP address 192.168.1.1. Each client machine dynamically allocates the IP address and the network is in good condition. The proxy mode is required to interconnect clients with the Internet and provide internal DNS resolution for schools. Take our school as an example. The proxy server address is 192.168.1.254, And the DNS server address is 192.168.1.1, which is the same as DHCP. To quickly bind, consolidate, and these two services, we need to use a very practical application-Dual dhcp dns Server. Dual DHCP DNSServer is a DHCP/DNS service consolidation program designed for SOHO networks and small LAN networks. It features powerful functions, convenient operation, and low system resource usage.

1. Download and install

1) To http://freshmeat.net/redir/dualdhcpdnsserver/60635/url_homepage/dhcp-dns-

Server downloads the dualserverv2.1.tar package and uses

# Tar xzvf dualserverV2.1.tar command Decompression

2) with the root permission, run the following command to run dualserver:

/Dualserver? V

Dualserver runs in two modes: Debug mode and Daemon mode. Generally, you can use the-v option to complete the operation.

Dualserver running, detailed procedures are displayed. If we want to automatically run

Dualserver, which can be added to the/etc/rc. d/rc. local or/etc/inittab file.

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