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mediumaddressing~30 min

Replace four routes with one

A router carries four separate static routes to four contiguous /24s. Collapse them into the single summary route that covers exactly those networks.

Scenario

r1 reaches four networks behind r2 and currently carries a separate static route for each: 10.1.0.0/24, 10.1.1.0/24, 10.1.2.0/24, 10.1.3.0/24. They're contiguous, so one summary route can replace all four.

Your job

In r1/frr.conf, replace the four /24 static routes with the single summary route that covers exactly those four networks (and no more), via the same next hop 10.0.12.2.

What "done" looks like

A single static route that covers exactly those four /24s and nothing more, via the same next hop, with the four /24 routes removed.

Teaches: route summarization (supernetting). Four contiguous /24s aggregate into one shorter prefix, which shrinks the routing table without advertising address space you don't actually have.

What gets checked

Your solution is verified against each of these:

  • A single summary route replaces the four separate /24s
  • The summary covers all four /24 networks
  • The four individual /24 routes are gone, replaced by the summary

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