Link state information is isolated by default between different IS-IS processes on the same router.

Question

Options

• ATRUE
• BFALSE

• A
  71% (30)
• B
  29% (12)

Explanation

Each IS-IS process on a router maintains its own independent link-state database (LSDB), and by default, topology information does not leak or flow between processes - they operate as entirely separate routing domains on the same device. This isolation is by design, allowing network engineers to segment routing information (e.g., for different VRFs or administrative domains) without unintended cross-contamination. To share routes between IS-IS processes, you must explicitly configure route redistribution, which is an administrative action, not default behavior. Option B (FALSE) is incorrect because assuming shared state would misrepresent how IS-IS process separation works and could lead to dangerous misconfigurations in real networks.

Memory tip: Think of each IS-IS process as a separate silo - information stays locked inside unless you build a redistribution "bridge" between silos. No bridge = no sharing.

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