Lab Simulation 4 Guidelines This is a lab item in which tasks will be performed on virtual devices - Refer to the Tasks tab to view the tasks for this lab item. - Refer to the Topology tab to access t

Lab Simulation 4: Static Routing Explanation Overall Goal The lab establishes IP connectivity across four routers without dynamic routing protocols (no OSPF, EIGRP, etc.). Every router must be explicitly told how to reach remote networks. The key challenge: routing is bidirection

Submitted by eva_at· Mar 5, 2026IP Connectivity

Question

Lab Simulation 4 Guidelines This is a lab item in which tasks will be performed on virtual devices - Refer to the Tasks tab to view the tasks for this lab item. - Refer to the Topology tab to access the device console(s) and perform the tasks - Console access is available for all required devices by clicking the device icon or using the tab(s) above the console window - All necessary preconfigurations have been applied - Do not change the enable password or hostname for any device - Save your configurations to NVRAM before moving to the next item - Click Next at the bottom of the screen to submit this lab and move to the next question - When Next is clicked, the lab closes and cannot be reopened Topology Tasks Connectivity between four routers has been established. IP connectivity must be configured in the order presented to complete the implementation. No dynamic routing protocols are included. 1. Configure static routing using host routes to establish connectivity from router R3 to the router R1 Loopback address using the source IP of 209.165.200.230. 2. Configure an IPv4 default route on router R2 destined for router R4. 3. Configure an IPv6 default router on router R2 destined for router R4. Answer: Task 1: R3(config)#ip route 192.168.1.1 255.255.255.255 209.165.200.229 R2(config)#ip route 192.168.1.1 255.255.255.255 209.165.200.225 R1(config)#ip route 209.165.200.230 255.255.255.255 209.165.200.226 Verification R3#ping 192.168.1.1 .!!!! Task 2: R2(config)#ip route 0.0.0.0 0.0.0.0 209.165.202.130 Task 3: R2(config)#ipv6 route ::/0 2001:db8:abcd::2

Exhibits

Explanation

Lab Simulation 4: Static Routing Explanation

Overall Goal

The lab establishes IP connectivity across four routers without dynamic routing protocols (no OSPF, EIGRP, etc.). Every router must be explicitly told how to reach remote networks. The key challenge: routing is bidirectional - for a ping to succeed, both the request AND the reply must have a valid path.

Topology Context (inferred from the IP addresses)

R3 --- R2 --- R1 (Loopback: 192.168.1.1)
        |
        R4

Key interfaces/IPs:

R3's exit IP: 209.165.200.230 (source of the ping)
R3->R2 link: R2's side is 209.165.200.229
R2->R1 link: R1's side is 209.165.200.225, R2's side is 209.165.200.226
R2->R4 link: R4's side is 209.165.202.130 / 2001:db8:abcd::2

Task 1: Static Host Routes - R3 to R1's Loopback

Why host routes? A host route uses mask 255.255.255.255 (or /32) to match exactly one IP address - in this case, R1's loopback 192.168.1.1. This is more specific than a network route and is the precise tool when you need reachability to a single address.

Step 1 - R3:

R3(config)#ip route 192.168.1.1 255.255.255.255 209.165.200.229

Destination: R1's loopback (192.168.1.1/32)
Next-hop: 209.165.200.229 - R2's interface on the R3-R2 link
This tells R3: "To reach 192.168.1.1, send traffic to R2."
Without this: R3 has no idea where 192.168.1.1 is. The ping never leaves R3.

Step 2 - R2:

R2(config)#ip route 192.168.1.1 255.255.255.255 209.165.200.225

R2 receives the packet from R3 and must forward it onward to R1.
Next-hop: 209.165.200.225 - R1's interface on the R2-R1 link
Without this: The packet arrives at R2 and is dropped - R2 has no route to 192.168.1.1.

Step 3 - R1:

R1(config)#ip route 209.165.200.230 255.255.255.255 209.165.200.226

This is the return path. R1 receives the ping from source IP 209.165.200.230 (R3's exit address) and must know how to reply.
Next-hop: 209.165.200.226 - R2's interface on the R1-R2 link
Without this: R1 receives the ping but cannot reply - it drops the reply because it has no route back to 209.165.200.230. The ping shows .!!!! (first packet lost, ICMP unreachable or timeout, then R1 learns the path - but in static routing it never learns; you'd see .... without this route).

The R3#ping 192.168.1.1 result .!!!! confirms: the first packet was lost (while ARP resolved), then 4 succeeds. This is normal behavior.

Order matters: You must configure R3 first (traffic source), then R2 (transit), then R1 (return path). Though the routes don't depend on each other at config time, the question specifies this order for logical clarity and to match how a packet travels.

Task 2: IPv4 Default Route on R2 -> R4

R2(config)#ip route 0.0.0.0 0.0.0.0 209.165.202.130

0.0.0.0 0.0.0.0 is the default route - it matches any destination not covered by a more specific route (the "gateway of last resort").
Next-hop: 209.165.202.130 - R4's IPv4 address on the R2-R4 link
This tells R2: "For any unknown IPv4 destination, forward to R4."
Without this: Traffic destined for networks beyond R4 (e.g., the internet) would be dropped at R2 with "no route to host."

Task 3: IPv6 Default Route on R2 -> R4

R2(config)#ipv6 route ::/0 2001:db8:abcd::2

IPv6 equivalent of the default route. ::/0 means "all IPv6 addresses" (prefix length 0 = match everything).
Next-hop: 2001:db8:abcd::2 - R4's IPv6 address
IPv4 and IPv6 routing tables are completely separate on Cisco IOS. Configuring an IPv4 default route does nothing for IPv6 traffic.
Without this: All IPv6 traffic from R2 toward R4 is dropped, even though IPv4 works fine.

What Goes Wrong If Steps Are Skipped

Skipped Step	Symptom
R3's host route	Ping never initiates - R3 drops packet immediately
R2's host route	Ping dies at R2 - R3 sees only timeouts
R1's return route	R3 sees all timeouts - packet arrives at R1 but reply is dropped
IPv4 default route	R2 can't reach anything past R4 for IPv4
IPv6 default route	R2 can't reach anything past R4 for IPv6 (IPv4 still works)

Memory Tips

Bidirectional routing: Every ping needs a forward path AND a return path. Always ask: "Can the reply find its way back?"
Host route = /32: When you see 255.255.255.255, think "exactly one IP address." It's the most specific route possible.
Default route mnemonic: 0.0.0.0 0.0.0.0 = "zero knowledge, send it somewhere else." In IPv6: ::/0 = same idea.
Separate routing tables: IPv4 uses ip route, IPv6 uses ipv6 route. They never mix - if a task involves both, you need both commands.
Verify with ping: The .!!!! pattern on Cisco means the first probe timed out (normal for ARP) but subsequent probes succeeded - connectivity is working.

Topics

#Static Routing#Host Routes#Default Routes#IPv6 Routing

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