You are configuring MPLS traffic-engineering tunnels in the core.
Which two ways exist for the tunnel path across the core? (Choose two.)
Click on the arrows to vote for the correct answer
A. B. C. D. E.BE.
MPLS traffic engineering tunnels are used in service provider networks to optimize the use of network resources and provide better quality of service for critical applications. When configuring MPLS TE tunnels in the core, there are two ways to define the tunnel path:
Explicitly defined path: In this method, the path of the tunnel is explicitly configured by the network operator. The operator specifies the path that the tunnel will take through the network, hop by hop, using the tunnel path command. This allows for fine-grained control over the path that the tunnel takes, but can be time-consuming to set up and maintain.
Dynamic path option: In this method, the path of the tunnel is dynamically computed by the network using a routing protocol such as OSPF or ISIS. The network operator configures the tunnel with a set of constraints, such as bandwidth, latency, or link diversity, and the network computes the optimal path based on those constraints. This method is more automated and easier to manage, but may not provide the same level of fine-grained control as the explicitly defined path.
Answer A is incorrect because the dynamic path option is supported with both OSPF and IS-IS, not just IS-IS.
Answer B is correct because tunnels can be configured with either a dynamic path or explicitly defined path.
Answer C is incorrect because a zero bandwidth tunnel is a valid option. Zero bandwidth tunnels are used to reserve the path for traffic engineering purposes but do not actually carry any user data.
Answer D is correct because the bandwidth statement does create a hard reservation on the link. This means that the reserved bandwidth cannot be used by any other traffic, even if it is not being used by the tunnel.
Answer E is correct because tunnel links inherit IGP metrics by default unless overridden. This means that the path that the tunnel takes through the network will be influenced by the IGP metrics of the underlying links, unless the operator explicitly overrides them.