This chapter describes how to use the Novell® Internet Access Server Configuration utility (NIASCFG) to configure a backup call for a WAN connection.
A backup call enhances the reliability of your WAN. It ensures that permanent connections are maintained even if your primary WAN call destination goes down. As a result, you avoid unnecessary delays and maintain high reliability over your WAN connection.
Backup calls are also useful for ensuring filtering reliability. By default, all filters that currently affect a primary call will affect a configured backup call. If a primary call should go down, the configured backup call will maintain your filtering configurations.
You can configure additional filtering for the backup link to meet the specific needs of your site (refer to Chapter 15, "Configuring Filters,”). If you configure additional filtering, that filtering will be maintained on the backup link in addition to the automatically mapped filtering.
Optionally, the automatic mapping of filtering can be disabled with the LOAD FILTSRV NOBACKUP command. With automatic mapping of filtering disabled, you can configure a selective filtering scheme that is specific to the needs of the backup link (refer to Chapter 15, "Configuring Filters,”).
Backup calls must be PPP-based and the circuit information must be correctly specified. When you configure a backup call, you specify a backup WAN call destination to be used in the event that the primary WAN call destination becomes unavailable. The Novell Internet Access Server 4.1 routing software switches automatically to the backup WAN call destination if the primary WAN call destination goes down. When the primary connection is restored, the routing software switches to the primary WAN call destination and terminates the backup.
You specify a backup WAN call destination by configuring two existing WAN call destinations to have an association by which the routing software recognizes one as the primary destination and the other as its backup.
Primary connections can be over fixed or switched circuits. Backups are always over switched circuits.
This chapter describes the configuration of backup calls through the use of WAN call associations. It contains the following sections: