Static routing across three routers

Objective

H1 reaches H2 through R1, R2 and R3, each with a static route toward the far side.

Procedure

1. Run: pings answered. Click a ping packet near H2 and read its TTL.
2. Delete the route '10.0.0.0/24 via 10.0.2.1' from R3: replies are lost (no route back).

Theory

Each router forwards by longest-prefix match: directly connected networks first, then static routes ('network via next-hop'). Every router decrements the TTL, so a packet arriving at H2 has TTL 64 − 3 = 61. Return routes must exist too.

Network blocks used

2 × Host / PC, 3 × Router

More Computer Networks Lab experiments

• Traceroute: discovering the path with TTL
• TTL expiry and ICMP time-exceeded
• RTT and packet loss on a lossy link
• Packet size versus latency
• Queueing delay and loss on an overloaded link