2.1. Static and Dynamic Interface Settings
When to use static addressing and when to use dynamic addressing? These decisions are subjective, they depend on your accessed needs, your specific requirements. Having a policy, documenting it, and applying it consistently are usually more important than the specific decisions you make. In a traditional company LAN, this is an easier decision to make as you typically have fewer servers than other hosts. Provisioning and installation tools make providing static configurations to new hosts easy and using such tools will change your work flow and requirements. The following two sections are intended to provide guidance to those who have not already been through this decision-making process. For more information on automated configuration and management, see the OpenLMI section in the System Administrators Guide. The System Installation Guide documents the use of kickstart which can also be used for automating the assignment of network settings.
2.1.1. When to Use Static Network Interface Settings
Use static IP addressing on those servers and devices whose network availability you want to ensure when automatic assignment methods, such as DHCP, fail. DHCP, DNS, and authentication servers are typical examples. Interfaces for out-of-band management devices are also worth configuring with static settings as these devices are supposed to work, as far as is possible, independently of other network infrastructure.
For hosts which are not considered vital, but for which static IP addressing is still considered desirable, use an automated provisioning method when possible. For example, DHCP servers can be configured to provide the same IP address to the same host every time. This method could be used for communal printers for example.
2.1.2. When to Use Dynamic Interface Settings
Enable and use dynamic assignment of
IP addresses and other network information whenever there is no compelling reason not to. The time saved in planning and documenting manual settings can be better spent elsewhere. The
dynamic host control protocol (
DHCP) is a traditional method of dynamically assigning network configurations to hosts. See
Section 9.1, “Why Use DHCP?” for more information on this subject.
Note that NetworkManager will start the DHCP client, dhclient, automatically.
2.1.3. Selecting Network Configuration Methods
