Cisco IOS: Can I Have MPLS TE Tunnels Use FRR When Using Dynamic Paths?
MPLS Traffic Engineering (TE) Tunnels are used to route traffic in a network according to predetermined paths. These paths can be static or dynamic, and they can be configured to use Fast Reroute (FRR) in the event of link or node failure. FRR is an important feature of MPLS TE Tunnels, as it helps ensure that traffic is still able to traverse the network quickly and reliably.
The question is, can MPLS TE Tunnels use FRR when using dynamic paths? The answer is yes. It is possible to configure dynamic paths in a network that use FRR as a backup in case of failure. This is done by configuring the tunnel to use dynamic path selection, or DPS.
DPS is a feature of Cisco IOS that allows for dynamic path selection. It uses a combination of metrics to determine the best path for a given tunnel at any given time. These metrics include metrics such as bandwidth, delay, jitter, and cost. DPS also allows for the configuration of FRR as a backup in case of link or node failure.
When configuring FRR with DPS, it is important to remember that the FRR will only be used if the primary path fails. If the primary path is still functioning, the FRR will not be used. This is because DPS will always select the path with the best metrics, and the FRR is only used as a backup.
In order to configure FRR with DPS, it is necessary to configure a static route for the tunnel. This static route will be used as the primary path for the tunnel. The FRR will then be configured as a backup route in case of failure.
It is important to note that FRR is not foolproof. While it is a useful feature to have, it is not a replacement for a well-designed network. In order to ensure that traffic is routed reliably and quickly, it is important to design the network with redundancy in mind. FRR can be used as an additional layer of protection in the event of failure, but it is not a substitute for careful planning.
In summary, it is possible to configure MPLS TE Tunnels to use FRR when using dynamic paths. This can be done by configuring a static route for the tunnel, followed by configuring FRR as a backup route. It is important to remember that FRR is not foolproof, and it should not be used as a substitute for a well-designed network.