Computer Networks · M2 · mocks

Q4 · RIP metric and next hop

M2 mock C

Q1(a)+Q1(b) compulsory; choose any two of Q2/Q3/Q4 · 10 marks attempted

Question. For a destination Z, RIP neighbour B advertises metric 15 and neighbour C advertises metric 4. Each local link adds one hop. Compute both candidate metrics and the selected route. [3 practice marks]

Answer

Given

B advertises 15; C advertises 4; each local cost=1. RIP infinity=16.

To find

Candidate metrics and usable next hop.

Formula and why

\text{candidate}=\min(16,1+\text{advertised metric})LaTeX: \text{candidate}=\min(16,1+\text{advertised metric})

RIP caps its metric at 16, representing unreachable.

Step-by-step solution

  1. Via B: min(16,1+15)=16 → unreachable.
  2. Via C: min(16,1+4)=5 → reachable.
  3. Select C, the finite lower-metric route.

Final answer: route via C at metric 5; B’s route is unreachable.