MPLS-Enabled Applications: Emerging Developments and New Technologies

13.4. CONFIGURATION ERRORS

Configuration errors are a common source of problems in network. Their impact can range from a service not coming up to traffic being routed to the wrong destination. There are two ways to deal with configuration errors. The first is to prevent the problem from happening in the first place, by improving the configuration process and by building mechanisms to reduce the amount of configuration needed to deploy a service. The second is to detect and report the misconfiguration, and try to protect the network from its ill effects. Let us discuss these two approaches separately below.

13.4.1. Preventing configuration errors

The basic idea behind preventing configuration errors is simple: fewer and simpler configuration statements means less probability for an error. Here are a few of the techniques used by various commercial implementations to put this idea into practice:

• Minimize the amount of configuration that must be applied to enable a feature. The more configuration statements required, the bigger the chance of an error, especially when the different statements are sprinkled in several places in the configuration file. For example, recall from the L3VPN chapter (Chapter 7) that the definition of a VRF requires both an import and an export policy. For simple any-to-any connectivity, the two are often the same. Therefore, rather than requiring an explicit listing of each, both could be configured in one statement.

• Use intuitive configuration statements. ...