| ⬅️ Back to Table of Contents |
|---|
This lab introduces static routing in a multi-router environment.
A simple topology with multiple routers is used, where routes between networks are manually configured using static routes.
📸 Screenshot:
- Understand the purpose of static routing
- Configure static routes between routers
- Compare static routing with dynamic routing
- Verify end-to-end connectivity using static routes
Devices
- 3 Routers (R1, R2, R3)
- PCs (optional, for connectivity testing)
Links
- Point-to-point connections between routers
- Each router connects to a unique LAN
| Device | Interface | Network |
|---|---|---|
| R1 | LAN | 192.168.1.0/24 |
| R1–R2 | WAN | 10.0.12.0/30 |
| R2–R3 | WAN | 10.0.23.0/30 |
| R3 | LAN | 192.168.3.0/24 |
- Static routing
- Next-hop IP address
- Directly connected vs remote networks
- Administrative distance
- Configure IP addressing on all router interfaces
- Manually configure static routes on each router
- Use next-hop IP addresses for route definition
ROUTER(config)# ip route <destination-network> <subnet-mask> <next-hop-ip>*(Repeat static route configuration for all remote networks)
📸 Screenshot:
(HQ)
(PRIME)
(BACK)
(BRANCH)
(SERVER)
- In CML I choosed PRIME router with the AD is lower than BACK Router.
📸 Screenshot:
- By
show ip static routecommand (Not available in Packet Tracer) we can actually which route is active [A] and which is none active [N], the none active route is acting like a backup route in the topology.
- Verify routing table:
show ip route
- Verify static routes:
show ip route static
- Test connectivity using ping between LANs
📸 Screenshot:
(Test connectivity between hosts)
(Traceroute to see which path would the ICMP Packets should be going through)
(Loopback in R_SERVER could be known as DNS)
(As expected the ICMP Packets go through the path with lowest AD - in this case is the path to R_PRIME)
(By assigning a higher AD to the redundant link, I created a Floating Static Route. This ensures the backup path stays dormant; no ICMP packets or data flows will transit this link unless the primary route is removed from the routing table due to a failure).
📸 Screenshot:
(R1_HQ changing to the Backup Path with AD from [1/0] -> [5/0])
(Because it is take only 1 route via loopback 0 between R_BRANCH - R_SERVER so there is no changing to the different path here)
(ICMP Packets now only go through Backup Path)
Caution
- Static routing is fundamentally "blind" to remote network changes. In this multi-router topology, I observed a critical limitation: Asymmetric Routing.
📸 Screenshot:
(Link between R_PRIME - R_BRANCH is still maintaining UP)
(Ping suddenly stop when shut down 1 primary link of total 2 between src and dst Routers & not changing to backup path too)
Warning
- When a primary link fails, the local router successfully switches to the floating static path. However, the remote router remains unaware of the failure and continues to forward return traffic toward the dead link. Without a mechanism to communicate link states between nodes, the data simply drops into a routing black hole.
- Manual path management is clearly not scalable for high-availability environments...
Tip
That’s why we will be deploying Dynamic Routing Protocols in the next lab. 😉
- Routers can reach remote networks using static routes
- Routing tables contain manually configured routes
- End devices can communicate across different networks
- Missing static routes on intermediate routers
- Incorrect next-hop IP address
- Overlapping or incorrect network statements
- Forgetting that static routes do not adapt automatically to topology changes
Note
- Static routing requires manual configuration and does not scale well in large networks.
- This lab helps build a foundation for understanding dynamic routing protocols such as RIP, EIGRP and OSPF.
| ⬅️ Previous Lab | 🏠 Main Menu | Next Lab ➡️ |
|---|