Refer to the exhibit. Router 1 resides in a different data center than Router 2 and Router 3. Router 1 is running the IS-IS routing protocol, and it is preconfigured with LDP and segment routing. Whic

Question

Exhibit

Options

• Ainterface GigabitEthernet0/0/1
• Binterface GigabitEthernet0/0/1
• Cinterface GigabitEthernet0/0/1
• Dinterface GigabitEthernet0/0/1

• A
  9% (3)
• B
  3% (1)
• C
  74% (25)
• D
  15% (5)

Explanation

TI-LFA (Topology-Independent Loop-Free Alternates) is an IS-IS fast-reroute mechanism that pre-computes backup paths using segment routing, providing protection against link or node failures with sub-50ms convergence. The requirement specifies implementing TI-LFA only on the link to Router 2 (GigabitEthernet0/0/1) WITHOUT disrupting traffic to Router 3. To achieve interface-specific TI-LFA without affecting other interfaces, the configuration must be applied at the interface level within the IS-IS process, not globally. The correct approach (Option C) configures TI-LFA under the specific interface context in router isis 111, using commands like 'fast-reroute per-prefix' and 'fast-reroute ti-lfa'. Applying it globally (Options A or B variations) would affect all IS-IS interfaces including the link to Router 3, potentially causing traffic disruption during the configuration change. LDP and SR are already preconfigured, so the engineer only needs to enable TI-LFA on the targeted interface.

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