Configuring & Troubleshooting Static Routes in Cisco IOS: Multi-Router CCNA Lab Guide

Why does configuring a static route on Router 1 to reach Router 2's LAN still result in 100% ping timeouts? Because IP routing is unidirectional per hop—every router along the forward path AND the return path must know how to reach the other side.

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A router automatically knows how to reach directly connected subnets (C)—any subnet attached to one of its own active (up/up) interfaces. However, a router has zero automatic knowledge of remote subnets separated by one or more intermediate routers unless an administrator either:

1. Configures Static Routes (ip route), or
2. Enables a dynamic routing protocol (such as OSPF, EIGRP, or BGP).

Static routing is a core requirement of the Cisco CCNA (200-301) exam (Domain 3.3: Configure and verify IPv4 and IPv6 static routing). In this lab guide, we cover the exact Cisco IOS syntax for network static routes, host routes (/32), and default routes (0.0.0.0/0), why return routes are essential, and how to build and test a multi-router static routing lab in the Web Packet Tracer & Network Simulator.

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1. Cisco IOS ip route Syntax & Route Types

In Global Configuration mode (R1(config)#), a static route is configured with:

R1(config)# ip route <destination-network> <subnet-mask> <next-hop-ip>

• <destination-network>: The Network ID of the remote subnet you want to reach (e.g., 192.168.2.0). (Note: If you enter a host IP inside the subnet, our simulator normalizes it via bitwise AND, while physical Cisco IOS rejects inconsistent address/mask pairs with % Inconsistent address and mask—so always use the exact Network ID!)
• <subnet-mask>: The dotted-decimal subnet mask of the remote network (e.g., 255.255.255.0).
• <next-hop-ip>: The IPv4 address of the neighboring router's interface on a shared connected subnet that leads toward the destination (e.g., 10.0.12.2).

Three Essential Static Route Variants for the CCNA Exam

Static Route Type	Example Command	Prefix Length	When to Use
1. Network Static Route	ip route 192.168.2.0 255.255.255.0 10.0.12.2	/1 – /30	Routing traffic to a specific remote LAN or VLAN subnet.
2. Host Static Route	ip route 192.168.2.99 255.255.255.255 10.0.12.2	/32	Routing traffic to a single specific server or loopback IP address.
3. Default Static Route	ip route 0.0.0.0 0.0.0.0 10.0.12.2	/0	"Quad-Zero" route matching any destination IP not matched by a more specific route (used on stub/branch routers or ISP edges).

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2. How Next-Hop Recursive Lookup Works on Ethernet Links

When you configure a next-hop static route such as:

ip route 192.168.2.0 255.255.255.0 10.0.12.2

Notice that the command specifies the Next-Hop IP (10.0.12.2), not an outgoing interface name!

When R1 needs to forward a packet to 192.168.2.10:

1. Lookup 1: R1 matches S 192.168.2.0/24 [1/0] via 10.0.12.2.
2. Lookup 2 (Recursive Lookup): R1 looks up the next-hop IP 10.0.12.2 against its Connected (C) routes and finds C 10.0.12.0/30 is directly connected, GigabitEthernet0/1.
3. Egress & ARP: R1 transmits the packet out of Gi0/1, using ARP to resolve the MAC address of 10.0.12.2 (the neighbor router's interface).

What if the Next-Hop IP is not reachable via any active Connected (C) subnet?
Then the static route cannot resolve an egress interface, and any packet matching it will be dropped!

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3. Hands-On Multi-Router Lab in Web Packet Tracer

Let us build a complete 2-Router, 3-Subnet topology in the Web Packet Tracer & Network Simulator:

  [Subnet A: 192.168.1.0/24]      [Transit Link: 10.0.12.0/30]      [Subnet B: 192.168.2.0/24]
PC1 (.10) ── SW1 ── (.1) R1 (.1) ──────────────────────────── (.2) R2 (.1) ── SW2 ── PC2 (.10)
                    Gi0/0  Gi0/1                              Gi0/0  Gi0/1

Step 1: Build and Cable the Topology

1. Open Web Packet Tracer and click Clear Canvas.
2. Click + PC twice (PC1, PC2), + Switch (8p) twice (SW1, SW2), and + Router (3p) twice (R1, R2).
3. Cable the devices (by dragging port handles on the canvas or using the Quick Port Cabling bar):
   • PC1 (eth0) $\leftrightarrow$ SW1 (Fa0/1)
   • SW1 (Fa0/2) $\leftrightarrow$ R1 (Gi0/0)
   • R1 (Gi0/1) $\leftrightarrow$ R2 (Gi0/0) (Router-to-Router Transit Link)
   • R2 (Gi0/1) $\leftrightarrow$ SW2 (Fa0/1)
   • SW2 (Fa0/2) $\leftrightarrow$ PC2 (eth0)

Step 2: Configure PCs

• PC1: IP 192.168.1.10, Subnet Mask 255.255.255.0, Default Gateway 192.168.1.1
• PC2: IP 192.168.2.10, Subnet Mask 255.255.255.0, Default Gateway 192.168.2.1

Step 3: Configure R1 Interfaces & Static Route

Open the R1 console tab and paste/enter:

enable
configure terminal
interface Gi0/0
 ip address 192.168.1.1 255.255.255.0
 no shutdown
exit
interface Gi0/1
 ip address 10.0.12.1 255.255.255.252
 no shutdown
exit
ip route 192.168.2.0 255.255.255.0 10.0.12.2
end
show ip route

Step 4: Configure R2 Interfaces (First Without Return Route to Observe the Failure!)

Open the R2 console tab and configure only its interfaces:

enable
configure terminal
interface Gi0/0
 ip address 10.0.12.2 255.255.255.252
 no shutdown
exit
interface Gi0/1
 ip address 192.168.2.1 255.255.255.0
 no shutdown
end

Now switch to Step Mode and run ping 192.168.2.10 from PC1!

• Watch the Packet Trace Event Log:
  1. PC1's ICMP Echo Request reaches R1, is routed across 10.0.12.0/30 to R2, and arrives all the way at PC2 (192.168.2.10)!
  2. PC2 generates an ICMP Echo Reply (src: 192.168.2.10 -> dst: 192.168.1.10) and sends it to its default gateway R2.
  3. R2 drops the Echo Reply (DROP (No route to 192.168.1.10)) because R2 has no static route back to 192.168.1.0/24!

Step 5: Add the Return Static Route on R2

On R2, add the return route:

configure terminal
ip route 192.168.1.0 255.255.255.0 10.0.12.1
end
show ip route

Now run ping 192.168.2.10 and tracert 192.168.2.10 from PC1—all 4 ICMP probes succeed (0% loss), and tracert lists every hop (192.168.1.1 $\rightarrow$ 10.0.12.2 $\rightarrow$ 192.168.2.10)!

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4. Common Static Routing Troubleshooting Checklist

If a static route is not working in a CCNA lab, check these 4 common mistakes:

1. Missing Return Route: Router A knows how to reach Subnet B, but Router B does not have a route back to Subnet A (or back to the transit subnet).
2. Wrong Next-Hop IP (Using Local Interface IP Instead of Neighbor's IP): On R1 (10.0.12.1), the next-hop IP must be R2's IP (10.0.12.2), never R1's own IP (10.0.12.1).
3. Shut Down Transit Interface: If R1 Gi0/1 or R2 Gi0/0 is still administratively down (show ip interface brief), the connected route 10.0.12.0/30 does not exist in show ip route, so the static route cannot resolve an egress port.
4. Routing Loop Between Default Routes: If R1 has ip route 0.0.0.0 0.0.0.0 10.0.12.2 and R2 also has ip route 0.0.0.0 0.0.0.0 10.0.12.1, any packet to an unknown IP will bounce back and forth between R1 and R2 until its IPv4 TTL decrements to 0 (TTL expired in transit).

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5. Legitimate Sources & Standards References

• IETF RFC 1812: Requirements for IP Version 4 Routers (June 1995 — Static route forwarding, next-hop resolution, and TTL loop mitigation).
• Cisco IOS IP Routing: Protocol-Independent Command Reference: ip route, no ip route, and show ip route command specifications.
• Cisco CCNA 200-301 Exam Topics (v1.1): Domain 3.0 IP Connectivity (3.3 Configure and verify IPv4 and IPv6 static routing: Default route, Network route, Host route, Floating static).

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6. CCNA 200-301 Exam Prep: Questions & Detailed Answers

Question 1

In the topology PC1 (192.168.1.10/24) — R1 (Gi0/0: 192.168.1.1/24, Gi0/1: 10.0.12.1/30) — R2 (Gi0/0: 10.0.12.2/30, Gi0/1: 192.168.2.1/24) — PC2 (192.168.2.10/24), which command on R1 correctly configures a static network route to reach PC2's subnet?

• A. R1(config)# ip route 192.168.2.0 255.255.255.0 10.0.12.1
• B. R1(config)# ip route 192.168.2.0 255.255.255.0 10.0.12.2
• C. R1(config)# ip route 192.168.2.0 255.255.255.0 192.168.2.1
• D. R1(config)# ip route 10.0.12.0 255.255.255.252 192.168.2.1

Correct Answer: B
Explanation: On R1, the remote destination network is 192.168.2.0 with mask 255.255.255.0, and the next-hop IP is the neighboring router R2's interface IP on the shared transit link (10.0.12.2). Option A mistakenly uses R1's own IP (10.0.12.1), and Option C uses R2's far-side LAN IP (192.168.2.1), which R1 has no connected route to reach.

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Question 2

Which Cisco IOS command configures a static Host Route to reach a single specific monitoring server at 172.16.50.200 via next-hop 10.1.1.2?

• A. ip route 172.16.50.200 255.255.255.0 10.1.1.2
• B. ip route 172.16.50.200 255.255.255.252 10.1.1.2
• C. ip route 172.16.50.200 255.255.255.255 10.1.1.2
• D. ip route 172.16.50.200 0.0.0.0 10.1.1.2

Correct Answer: C
Explanation: A Host Route targets a single IPv4 address using a /32 subnet mask (255.255.255.255), matching all 32 bits of 172.16.50.200.

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Question 3

Which command configures a Default Static Route ("Gateway of Last Resort") on a Cisco IOS router pointing to an ISP next-hop router at 203.0.113.1?

• A. ip default-gateway 203.0.113.1
• B. ip route 0.0.0.0 0.0.0.0 203.0.113.1
• C. ip route 255.255.255.255 255.255.255.255 203.0.113.1
• D. ip route default 203.0.113.1

Correct Answer: B
Explanation: A default static route in IPv4 uses the "quad-zero" prefix and mask (0.0.0.0 0.0.0.0, or /0): ip route 0.0.0.0 0.0.0.0 203.0.113.1. Because a /0 mask requires 0 matching bits, it matches every possible IPv4 destination address, but only when no more-specific route (/1 through /32) matches in the routing table. (ip default-gateway in Option A is used on a Layer-2 switch for management traffic or when ip routing is disabled.)

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Question 4

When R1 has the static route ip route 192.168.2.0 255.255.255.0 10.0.12.2 and forwards a packet destined for 192.168.2.10 out of its Ethernet interface Gi0/1, which IP address does R1 send an ARP Request for on Gi0/1?

• A. 192.168.2.10
• B. 192.168.2.0
• C. 10.0.12.2
• D. 10.0.12.1

Correct Answer: C
Explanation: When a route specifies a next-hop IP (10.0.12.2), the router resolves the Layer-2 MAC address of the next-hop IP (10.0.12.2) via ARP on the egress interface (Gi0/1). The Layer-3 Destination IP inside the IPv4 packet remains 192.168.2.10, while the Layer-2 Destination MAC is set to 10.0.12.2's MAC address.

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Question 5

An engineer accidentally entered ip route 192.168.2.0 255.255.255.0 10.0.12.99 on R1, and now wants to remove that specific static route before adding the correct one. Which command removes it?

• A. R1# clear ip route 192.168.2.0
• B. R1(config)# no ip route 192.168.2.0 255.255.255.0 10.0.12.99
• C. R1(config)# delete ip route 192.168.2.0
• D. R1(config-if)# no ip route

Correct Answer: B
Explanation: Static routes are removed in Global Configuration mode ((config)#) by prefixing the exact route statement with no: no ip route 192.168.2.0 255.255.255.0 10.0.12.99. (clear ip route in Privileged EXEC mode only refreshes the dynamic routing table; it does not delete static route commands from running-config.)