📘 CCNA 200-301 v1.1
3.3 Configure and verify IPv4 and IPv6 static routing
3.3.b Network route
✅ 1. What is a Network Route?
A network route is an entry in a router’s routing table that tells the router how to reach a specific network.
When a router receives a packet, it checks the destination IP address in the packet and looks for a matching route in its routing table.
If it finds a route that matches the destination network, the router forwards the packet through the correct interface (and possibly to the next-hop router).
✅ 2. Types of Routes in a Router’s Routing Table
A router’s routing table can contain different kinds of routes:
| Type | Description | Example |
|---|---|---|
| Directly Connected Route | Automatically added when an interface is configured with an IP address and is up. | 192.168.1.0/24 is directly connected via GigabitEthernet0/0 |
| Static Route | Manually configured by an administrator. | ip route 10.1.1.0 255.255.255.0 192.168.1.1 |
| Dynamic Route | Learned automatically using routing protocols (like OSPF, EIGRP, RIP). | O 172.16.0.0/16 [110/2] via 10.0.0.2 |
| Default Route | Used when no other route matches. | ip route 0.0.0.0 0.0.0.0 192.168.1.254 |
For this section (3.3.b), we focus on static network routes — how to configure and verify them.
✅ 3. What is a Static Network Route?
A static network route is a manually entered route that tells the router how to reach a specific network.
It is not learned dynamically.
It stays in the routing table until the administrator removes it or the interface goes down (if directly tied to that interface).
✅ 4. IPv4 Static Network Route Configuration
➤ Syntax:
Router(config)# ip route <destination-network> <subnet-mask> <next-hop-address or exit-interface>
➤ Example:
Router(config)# ip route 10.10.20.0 255.255.255.0 192.168.1.2
Explanation:
- 10.10.20.0 → Destination network you want to reach
- 255.255.255.0 → Subnet mask for that network
- 192.168.1.2 → Next-hop IP address (the address of the next router)
This means:
“To reach the 10.10.20.0/24 network, send packets to the next-hop router at 192.168.1.2.”
✅ 5. IPv6 Static Network Route Configuration
➤ Syntax:
Router(config)# ipv6 route <destination-network>/<prefix-length> <next-hop-address or exit-interface>
➤ Example:
Router(config)# ipv6 route 2001:DB8:1:20::/64 2001:DB8:1:10::2
Explanation:
- 2001:DB8:1:20::/64 → Destination IPv6 network
- 2001:DB8:1:10::2 → Next-hop IPv6 address
This means:
“To reach the network 2001:DB8:1:20::/64, send packets to next-hop router 2001:DB8:1:10::2.”
✅ 6. Static Route Options
You can configure a static route using different options depending on your network design.
| Option | Description | Example |
|---|---|---|
| Next-hop IP address | Router forwards packets to this next-hop IP. | ip route 10.1.1.0 255.255.255.0 192.168.1.2 |
| Exit interface | Router sends packets directly out of the specified interface. | ip route 10.1.1.0 255.255.255.0 GigabitEthernet0/1 |
| Next-hop + Exit interface | Combines both, gives better control and stability. | ip route 10.1.1.0 255.255.255.0 GigabitEthernet0/1 192.168.1.2 |
⚠️ Important: For point-to-point interfaces (like serial links), you can use the exit interface directly.
For multi-access networks (like Ethernet), it’s safer to use the next-hop IP so ARP can resolve it properly.
✅ 7. Floating Static Route
A floating static route is a backup static route.
It is used only if the main (primary) route fails.
➤ How it works:
You give it a higher Administrative Distance (AD) value.
➤ Example:
Router(config)# ip route 10.10.10.0 255.255.255.0 192.168.1.2 5
- The “5” is the Administrative Distance.
- Default AD of static routes = 1.
- So this route will be used only if the main route (with AD 1) is unavailable.
✅ 8. How to Verify Network Routes
You can use these Cisco IOS commands to verify and troubleshoot routes:
| Command | Description | Example Output |
|---|---|---|
| show ip route | Displays the IPv4 routing table | S 10.10.20.0/24 [1/0] via 192.168.1.2 |
| show ipv6 route | Displays the IPv6 routing table | S 2001:DB8:1:20::/64 [1/0] via 2001:DB8:1:10::2 |
| ping | Tests connectivity to a destination | ping 10.10.20.1 |
| traceroute | Shows path packets take to reach destination | traceroute 10.10.20.1 |
✅ 9. Routing Table Codes
When you view the routing table, you will see codes that identify route types.
| Code | Meaning |
|---|---|
| C | Directly connected |
| S | Static route |
| R | RIP route |
| O | OSPF route |
| D | EIGRP route |
| L | Local route (IP of router interface) |
For example:
S 10.10.20.0/24 [1/0] via 192.168.1.2
- S → Static route
- 10.10.20.0/24 → Destination network
- [1/0] → Administrative Distance / Metric
- via 192.168.1.2 → Next-hop address
✅ 10. Removing a Static Route
To remove a static route, use the no form of the command:
Router(config)# no ip route 10.10.20.0 255.255.255.0 192.168.1.2
This deletes that route from the routing table.
✅ 11. When to Use Static Network Routes
Static routes are commonly used in:
- Small networks (less complex)
- Stub networks (only one path to reach outside)
- Default routes
- Backup routes (floating static)
- Security-sensitive networks (manual control over paths)
✅ 12. Advantages and Disadvantages
| Advantages | Disadvantages |
|---|---|
| Simple and easy to configure | Not scalable in large networks |
| No extra CPU or memory usage | Must be manually updated when topology changes |
| Very secure (no advertisement of routes) | Error-prone if many routes are added manually |
✅ 13. Summary (Key Points for CCNA Exam)
- A network route defines how to reach a remote network.
- Static routes are manually configured by the admin.
- Syntax for IPv4:
ip route <network> <mask> <next-hop or interface> - Syntax for IPv6:
ipv6 route <network>/<prefix-length> <next-hop or interface> - Verification commands:
show ip route,show ipv6 route,ping,traceroute. - Floating static routes are used as backups (higher AD).
- Static routes are reliable in small or stable networks but not scalable for large dynamic networks.
