2.1 Explain characteristics of routing technologies

📘CompTIA Network+ (N10-009)

What Is Static Routing?

Static routing is a routing method where the network administrator manually configures routes on a router.
These routes tell the router exactly where to send traffic for specific networks.

There is no automatic learning
Routes stay in the routing table until removed or changed by the administrator
It gives full control over how traffic moves inside a network

Static routing is often used in small networks, point-to-point links, stub networks, or places where network paths rarely change.

Key Characteristics of Static Routing

✔ 1. Manually Configured

All routes are entered by the administrator using router commands.
Example (Cisco syntax):

ip route <destination network> <subnet mask> <next-hop IP or exit interface>

✔ 2. Predictable and Consistent

The router always follows the static route unless the administrator edits it.
There is zero chance of unexpected route changes.

✔ 3. No Routing Updates

Static routes:

Do not send updates
Do not communicate with neighboring routers
This saves bandwidth and reduces processing load.

✔ 4. Low Overhead

Because no routing protocol runs in the background, static routing:

Uses very little CPU
Uses no additional memory for dynamic learning

✔ 5. High Administrative Distance Preference

Static routes have an Administrative Distance (AD) of 1, which means:

They are preferred over most dynamic routing protocols
(Example: OSPF AD = 110, RIP AD = 120)

✔ 6. Works in Simple or Stable Topologies

Static routing is ideal when:

The network has only one exit path
There is a predictable network design
No frequent changes are expected

Key Components of a Static Route

When you configure a static route, you define:

1. Destination Network

The network you want to reach
Example: 192.168.10.0

2. Subnet Mask

Defines the size of the network
Example: 255.255.255.0

3. Next-Hop IP Address OR Exit Interface

This tells the router where to forward packets.

Next-hop IP = the IP address of the next router
Exit interface = the interface used to send the packet out

Types of Static Routes (Important for the Exam)

1. Standard Static Route

A route pointing to a specific destination network

ip route 192.168.50.0 255.255.255.0 10.1.1.2

2. Default Static Route (0.0.0.0/0)

This route is used when the router does not know where to send traffic.
It sends all “unknown” traffic to a specific next hop.

It’s often used to reach:

The internet
An upstream gateway

Example:

ip route 0.0.0.0 0.0.0.0 10.1.1.1

3. Floating Static Route

A static route with a higher Administrative Distance than dynamic routes.
Used as a backup route.

Example:

ip route 192.168.20.0 255.255.255.0 10.1.1.2 200

AD=200 → will be used only if the primary dynamic route fails.

4. IPv6 Static Routes

IPv6 also supports static routing.
Example:

ipv6 route 2001:db8:1::/64 2001:db8:10::1

Advantages of Static Routing

These are exam-important benefits:

✔ 1. Very Secure

Since no routing updates are exchanged, static routes cannot be influenced by malicious routing advertisements.

✔ 2. No Bandwidth Usage for Updates

Unlike OSPF or RIP, static routes use no bandwidth for route exchanges.

✔ 3. Predictable Control

Administrators decide exactly where traffic goes—ideal for tightly controlled networks.

✔ 4. Lower CPU/Memory Use

Routers do not need to calculate or process routing tables dynamically.

✔ 5. Good for Small or Stable Networks

Perfect for:

Branch networks
Firewall routing
Data center uplinks
Single-path networks

Disadvantages of Static Routing

These weaknesses are important for exam comparisons.

✘ 1. Does Not Adapt to Network Changes

If:

A router fails
A link goes down
A network is added or removed

Static routes do not update automatically.
The administrator must manually change them.

✘ 2. Not Scalable

Large networks may require hundreds or thousands of routes.
Manually configuring them is time-consuming and error-prone.

✘ 3. Difficult Troubleshooting

Misconfigured static routes can silently break connectivity.

✘ 4. Requires Good Network Knowledge

Administrators must fully understand:

Network topology
Next-hop relationships
IP addressing

When Static Routing Is Used (IT-Relevant Use Cases)

✔ 1. Small Office Networks

Where only one router connects to the ISP.

✔ 2. Stub Networks

A network that has only one exit point.
No need for dynamic routing.

✔ 3. Router-to-Firewall Connections

Static routes ensure traffic always moves in a controlled path.

✔ 4. Default Route to Internet

Almost every network uses a default static route toward its ISP.

✔ 5. Backup Routes (Floating Static Routes)

Used along with:

OSPF
EIGRP
BGP
to provide failover.

✔ 6. Security-Sensitive Environments

Where automatic route updates are not allowed.

Static Route Troubleshooting Tips (Exam-Relevant)

📌 1. Check Routing Table (`show ip route`)

Verify if the static route appears with an “S” flag.

📌 2. Ensure Next-Hop Is Reachable

A static route will not work if the next-hop device is unreachable.

📌 3. Verify Interface Status

If the exit interface is down, the static route becomes inactive.

📌 4. Check Overlapping Routes

More specific routes take priority over less specific ones.

Static Routing vs Dynamic Routing (Exam Comparison)

Feature	Static Routing	Dynamic Routing
Configuration	Manual	Automatic
Scalability	Low	High
Adaptability	Poor	Excellent
CPU/Memory Usage	Low	Medium/High
Security	High	Medium
Best Use Case	Small/stable networks	Large or frequently changing networks

Summary for the Network+ Exam

To pass the exam, remember:

Static routing requires manual configuration
It uses no routing updates
It is secure, predictable, and resource-efficient
Not suitable for large, changing networks
Supports standard, default, floating, and IPv6 static routes
Often used in small networks, stub networks, and ISP default routes

Static routing is all about control, predictability, and simplicity.