According to the information given in the picture, which of the following descriptions are correct? (Multiple choice)

Question

Options

• AR1 has a route to access 172.17.1.5
• BR1 does not have a route to access 172.17.1.5
• CA loop occurs when R1 accesses 172.17.1.5
• DThere is no problem with R1 accessing the path of 172.17.1.5

• A
  78% (32)
• B
  7% (3)
• D
  15% (6)

Explanation

Options A and C are both correct because they describe two simultaneously true conditions: R1's routing table contains an entry for 172.17.1.5 (making A true), but that route points to a next-hop router that in turn points back toward R1 for that same destination, creating a routing loop (making C true). A routing loop means packets bounce between routers indefinitely, incrementing TTL until dropped, so the destination is never actually reached.

Why B is wrong: B claims R1 has no route - but a routing table entry clearly exists; the problem is not absence of a route, but a flawed one.

Why D is wrong: D claims there is "no problem," which directly contradicts C - a loop is a serious forwarding problem that causes packet loss and wasted bandwidth.

Memory tip: Think of it as "a broken map vs. no map." A routing loop means R1 has a map (route exists → A correct), but the map sends you in circles (loop exists → C correct). Having a route and having a working route are two different things - this distinction is a favorite exam trap.

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