The configuration of the DHCP server is one of the simplest services in the Linux server configuration, and there are many related documents on the Web, but most of them simply explain the configuration. Although this document may not be perfect, I would like to be able to make it as clear as possible, and I hope that we can provide more valuable advice. For the DHCP work process, you can refer to the "DHCP workflow detailed (http://guoxuemin.blog.51cto.com/379574/163475)". The main topics we are going to talk about today are the following: 1. DHCP installation 2. Basic Configuration 3. Multi-scope and relay Agent configuration 4. DHCP server security 5. Management monitoring DHCP Server The system used in this document is CentOS5, and the DHCP server is not installed by default.
First,
DHCP
installationLinux defaults to installing DHCP clients, and you can use the command: Rpm-qa|grep DHCP to view relevant installation information. To configure the server as a DHCP server, You will also need to install the following packages: dhcp-3.0.5-18.el5.i386.rpm,dhcp-devel-3.0.5-18.el5.i386.rpm,dhcpv6-1.0.10-16.el5.i386.rpm. (Note that the version of the DHCP installation package differs depending on the operating system version.) The specific installation is as follows:
Second, the basic configurationBelow we use an example to illustrate the configuration of the DHCP server, a company's network is as follows: Using network segment 192.168.99.0/ 24, Gateway Address: 192.168.99.1,dns and DHCP server address: 192.168.99.9, the company domain name: GUOXUEMIN.CN,DHCP address pool is: 192.168.99.51-192.168.99.254, in addition, boss computer binding 192 .168.99.46 this address. 1. You can also create a new dhcpd.conf by copying/usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample to/etc/dhcpd.conf. 2. Configure the/etc/dhcpd.conf, as follows: # vi /etc/dhcpd.conf parameter Description: 1) Ddns-update-style: Defines the supported DNS dynamic update types. Optional Parameters: None: Dynamic update not supported, Interim:dns Interactive update mode, AD-HOC: Special DNS update mode. 2) ignore client-updates: Ignore client update. 3) subnet 192.168.99.0 netmask 255.255.255.0: Specifies the subnet of the configuration. 4) option Routers: Default gateway address. 5) option Subnet-mask: Sets the client subnet mask. 6) option Nis-domain: Specifies the name of the NIS domain to which it belongs. 7) option domain-name: Specify the domain name. 8) option domain-name-servers: Specifies the DNS server address. 9) option Time-offset: Specifies the client time offset to UTC. range DYNAMIC-BOOTP: Address pool IP range. One) default-lease-time: Default IP address lease time. Max-lease-time: The maximum value of the client IP lease time. host client: Defines the reserved clients address. hardware Ethernet: Network card MAC address. fixed-address: the reserved IP address. 3. Information about the client leased IP address is stored in the lease database, and you can use the command:cat /var/lib/dhcpd/dhcpd.leases to view the lease database information. Note that the newly installed lease database is empty, requires a DHCP server to run, and has data records after the client is used. 4. Client configuration: 1) The configuration of the Windows client does not have to say much, the Earth people know that you can use the command ipconfig /renew refresh the address; 2) Configure the Linux client # vi /etc/sysconfig/ Network-.s/ifcfg-eth0 changed Bootproto=none to Bootproto=dhcp. Use command: # Ifdown eth0; Ifup eth0 Restart the NIC. OK, the client can use DHCP to get the IP address.
three, multi-scope and relay Agent configurationNext, let's look at the configuration of multi-scope and relay agents, or an example. A company has two subnets 192.168.99.0/24 and 192.168.100.0/24,192.168.100.0/24 network segments that use a relay proxy server. 1. Multi-scope configuration This situation is in the VLAN network, often need, here we installed on the DHCP server two network cards, connect two subnets, if there is a three-tier switch does not require multiple network cards, but the configuration of the DHCP server is the same, only need to configure a three-tier switch. We can use Ifconfig to check the usage of the NIC: Server configuration such as: 2. Relay Agent configuration The Relay Agent computer also needs to install the DHCP-3.0.5-18.EL5.I386.RPM package, by default, the relay agent computer does not forward the client's request and needs to use the command dhcrelay command to specify the DHCP server before forwarding. Such as:
Four,
DHCP
security of the serverIf there is only one DHCP server on the network, once the server fails, all the clients in the network will be unable to obtain the IP address and the entire network will be paralyzed. To avoid this, we have to consider using a double-click Backup. When doing a two-machine backup, the scope of the DHCP server is divided into 80/20 rules, the master server manages 80% of the network IP address, and the secondary server manages 20% of the network IP address. In daily work, the allocation of TCP/IP information is done by the primary DHCP server, and the secondary DHCP server does not start working until the primary server is unavailable. Double-click Backup DHCP server method as described above, just as the configuration method, only in the partition of the address pool, the 80% address to the primary server division, 20% of the address to the secondary server division. We continue to take the first instance to illustrate that a secondary DHCP server is added to the first instance, and the primary DHCP server is configured as follows: The secondary DHCP server is configured as follows:
v. Management and Monitoring
DHCP
ServerThe configuration of DHCP is very simple, but for some of the brothers who are accustomed to using graphics, they may feel somewhat abstract. However, fortunately, we have the means to solve, you can use the GADMIN-DHCPD program, configure a graphical user interface. Let's take a look at the specific ways to do this:
1.
Environmental InspectionGADMIN-DHCPD requires GCC, Qt, GTK + and other software support, you can use the command rpm-qa|grep gcc; Rpm-qa|grep qt; Rpm-qa|grep GTK to check if these programs are installed in the system. In general, the GCC and QT system will be installed by default, but the GTK + system will not be installed by default, for example, my system does not install GTK +, let's look at the installation method of GTK +:
2.
Installing support software
GTK +1) GTK + requires the following software support to install:glib-2.12.10.tar.gz (: ftp://ftp.gtk.org/pub/glib/2.12/) atk-1.10.1.tar.gz (: FTP ://ftp.gtk.org/pub/gtk/v2.8/) freetype-2.3.9.tar.gz (: http://sourceforge.net/projects/ FreeType) fontconfig-2.4.2.tar.gz (:/http/www.fontconfig.org/release/) cairo-1.4.12.tar.gz (:// cairographics.org/releases/) pango-1.14.10.tar.gz (: ftp://ftp.gnome.org/pub/GNOME/sources/ Pango) libpng-1.2.10.tar.gz (: http://www.libpng.org/pub/png/libpng.html) gtk+-2.10.12.tar.gz (: ftp:// ftp.gtk.org/pub/gtk/v2.10/) 2) Set the environment variable in order to be able to find the corresponding library to compile during the installation, two environment variables are established first. Steps are as follows: # export ld_library_path=/usr/local/lib# export pkg_config_path=/usr/local/lib/pkgconfig3) Installation glib# tar zxvf glib-2.12.10.tar.gz# cd glib-2.12.10#./configure# make# make uninstall# make INSTALL4) Install atk# tar zxvf atk-1.10.1.tar.gz# cd atk-1.10.1#./configure# make# make INSTALL5) Install freetype# tar zxvf freetype-2.3.9.tar.gz# cd freetype-2.3.9#./configure# make# make install6) installation fontconfig# tar zxvf fontconfig-2.4.2.tar.gz# cd& nbsp fontconfig#./configure# make# make install7) Install the Cairo installation method, Ibid. 8) Install Pango installation method, ibid. 9) Install Libpng installation method, ibid. 10) Install the GTK + installation method, as above.
3.
installation
GADMIN-DHCPD
Software：http://mange.dynalias.org/linux/gadmin-dhcpd/# tar zxvf gadmin-dhcpd-0.4.2.tar.gz# cd gadmin-dhcpd#./configure# make# Make Install
4.
Use
GADMIN-DHCPD
SoftwareOn the command line, enter:/USR/LOCAL/SBIN/GADMIN-DHCPD, you can see the graphical configuration of the DHCP interface: The graphical configuration of the environment is set to complete, so that is not very convenient? OK,DHCP server to this deployment is complete.
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Linux Server Deployment Series four-DHCP
