Typical Application - Interface Backup Via Policy-Based Routing - Avaya G250 Administration

Typical application – interface backup via policy-based routing
In the previous typical application (see
interface on page 266), the backup interface command is used to specify a backup
interface. This typical application illustrates an alternative to the backup interface
command, using policy-based routing (PBR) which configures a routing scheme for specified
traffic based on configured characteristics of the traffic. Thus, policy-based routing can be used
in combination with object tracking to configure a backup mechanism for interfaces.
For an example that uses policy-based routing as an alternative to the backup interface
command, replace the last four lines of the previous typical application with the example below.
The example creates a next hop list that sends the specified traffic to the WAN Fast Ethernet
interface, which is running PPPoE encapsulation. If the WAN Fast Ethernet interface becomes
unavailable, the next hop list routes the traffic to the Serial interface 2/1:1. PBR list 801 is
created and assigned to interface VLAN 1, so that traffic defined in PBR list 801 passing
through interface VLAN 1 is routed according to the next hop list.
Note:
You can define a static route over the WAN Fast Ethernet interface running DHCP
Note:
client. Then, the static route uses as the next hop the default router learned from
the DHCP server. This is useful for GRE tunnels which are defined over the WAN
Fast Ethernet running DHCP client. It is necessary to define static routes in order
to prevent loops. Therefore, the IP route command allows configuration of static
routes over WAN Fast Ethernet running DHCP client.
Typical application – backup for the WAN Fast Ethernet
Object tracking
Issue 3 February 2007 269