Regardless of the configuration you intend to use, you need to completely install the 3-DNS hardware. This chapter reviews the hardware requirements, introduces the hardware, notes the environmental issues, and gives procedures for installing the hardware. It also provides basic information about configuration and management issues for redundant systems, multiple network interfaces, and DNS zone files.
The two basic tasks you must complete to get the 3-DNS installed and set up are as follows:
The 3-DNS comes with the hardware you need for installation and maintenance. However, you must provide standard peripheral hardware, such as a keyboard and monitor or serial terminal.
When you unpack the 3-DNS, make sure the following components are included:
If you purchase a hardware-based redundant system, you also receive one fail-over cable to connect the two units together (network-based redundant systems do not require a fail-over cable).
For each 3-DNS in the system, you need to provide the following peripheral hardware:
If you plan on performing remote administration from your own PC workstation, as most users do, we recommend that you have your workstation already in place. Keep in mind that the Setup utility prompts you to enter your workstation's IP address when you set up remote administrative access.
The 3-DNS is offered in a 2U hardware configuration. Before you begin to install the 3-DNS, you may want to quickly review the hardware poster that illustrate the controls and ports on the front and the back of a 2U 3-DNS.
A 3-DNS is an industrial network appliance, designed to be mounted in a standard 19-inch rack. To ensure safe installation and operation of the unit:
A DC-powered installation must meet the following requirements:
There are six basic steps to installing the hardware. You simply need to install the system in the rack, connect the peripheral hardware and the external and internal interfaces, and then connect the fail-over and power cables. If you have a unit with three or more network interface cards (NICs), be sure to review step 3.
Warning: Before connecting the power cable to a power supply, customers outside the US should make sure that the voltage selector is set appropriately. This check is necessary only if the 3-DNS has an external voltage selector.
Before you start the hardware setup, you may want to review the following items which address configuration and management issues for redundant systems, systems that use more than one network interface, and DNS zone file management.
If you are setting up a stand-alone unit, you need one IP address and host name for each of the interfaces you plan to connect to the network. If you are setting up a redundant system, you need the actual IP address for each interface in each unit. If you are connecting the redundant system to more than one network, you also need a shared IP alias for each interface.
Hardware-based fail-over is a redundant system that connects two 3-DNS units directly to each other using a fail-over serial cable. Network-based fail-over is a redundant system where two units are connected to each other either directly using an Ethernet cable, or indirectly via an Ethernet network. Of the two units in a redundant system, one runs as the active unit, managing all DNS resolution requests, and the other runs as the standby unit, waiting to take over in case the active unit fails and reboots. The communication between the units, such as fail-over notification, runs across either the fail-over cable in the hardware-based redundant system, or the network in the network-based redundant system.
When you run the Setup utility, it prompts you to enter the IP address of the other unit in the redundant system.
The 3-DNS tracks two key aspects of the system to validate system performance. In a redundant system, there are two events that indicate a system failure, and trigger a fail-over.
If you include a redundant system in a sync group, you specify the redundant system's shared IP address when you define the sync group.
The Setup utility automatically detects the number of interfaces installed in the 3-DNS. In most instances, you need to configure only one of the interfaces. If you want to configure an additional interface, you simply enter the same type of information that you entered for the first interface.
The 3-DNS now runs in three modes: node, bridge, and router. If you are running the 3-DNS in node mode, you only need to configure one interface. If you are running the 3-DNS in bridge mode, you use the additional interface to connect the 3-DNS to the authoritative DNS using either a cross-over cable, or through a separate switch or hub. In bridge mode, you do not need to configure the information in the Setup utility for the additional network interface. In router mode, you must configure two (or more) interfaces, on different subnets, in the Setup utility.
Note: For more information about the 3-DNS modes, refer to Configuring the 3-DNS mode, on page 4-8 .
If you choose to run the 3-DNS in node mode (that is, as the primary name server for your domain), the Setup utility asks you if you want to use the NameSurfer application as the primary name server for DNS zone files. We recommend that you always run NameSurfer as the primary name server for DNS zone files. When you define or modify wide IPs in the Configuration utility, NameSurfer automatically makes the corresponding changes to the DNS zone files. The NameSurfer application also provides you with easy management of high-level domain zone files unrelated to the wide IP configuration.
If you plan on transferring existing BIND files from a primary DNS server to the 3-DNS, refer to Importing BIND files to NameSurfer during an initial installation, on page 2-11 .
The type of system you have determines the options you have for remote command line administration:
If you want to use a serial terminal (in addition to a standard console) with the 3-DNS, you need only ensure that the serial terminal settings are as follows:
You can configure the 3-DNS to send email notifications to you, or to other administrators, using the Sendmail utility. The 3-DNS includes a sample Sendmail configuration file that you can use to start with, but you must customize the Sendmail setup for your network environment before you can use it.
Before you begin setting up Sendmail, you may need to look up the name of the mail exchanger for your domain. If you already know the name of the mail exchanger, refer to Setting up Sendmail, on page 3-7 , for details about setting up the sendmail utility itself.
You can use the nslookup command on any workstation that is configured for lookup. Once you find the primary IP address for your domain, you can find the mail exchanger for your domain.
Default Server: <server name>
The returned information includes the name of the mail exchanger. For example, the sample information shown in Figure 3.1 lists bigip.net as the preferred mail exchanger.
bigip.net preference = 10, mail exchanger = mail.domain.com
bigip.net nameserver = ns1.bigip.net
bigip.net nameserver = ns2.bigip.net
bigip.net internet address = 192.168.112.1
ns1.bigip.net internet address = 192.168.112.2
ns2.bigip.net internet address = 192.168.112.3
When you set up Sendmail, you must edit three configuration files. Since the 3-DNS does not accept email messages, you can use the crontab utility to purge unsent or returned messages and send them to yourself or another administrator.
0,15,30,45 * * * * root /usr/sbin/sendmail -q > /dev/null 2>&1
/usr/sbin/sendmail -bd -q30m
When you need to turn the 3-DNS completely off, you need to complete two tasks. The first task is to shut down the 3-DNS software. After you shut down the 3-DNS software, you can turn off the power to the system.
System is halted, hit reset, turn power off, or press return to reboot