Tutorial 13

Author: breezy-codes

_toc.yml

@@ -32,6 +32,8 @@ parts:
         - file: cisco/tutorial-series/tutorial10
         - file: cisco/tutorial-series/tutorial11
         - file: cisco/tutorial-series/tutorial12
+        - file: cisco/tutorial-series/tutorial13
+        - file: cisco/tutorial-series/tutorial14
 
       - file: cisco/handy-tips/index
         title: Handy Tips

cisco/handy-tips/tip5.md

@@ -1,4 +1,4 @@
-# 5 – How to Customise the Router-PT in Cisco Packet Tracer
+# 5 – How to Customise the Router-PT in Packet Tracer
 
 This guide shows you how to **customise a Router-PT or Router-PT-Empty** device in Cisco Packet Tracer by adding or removing network interface modules.
 

cisco/tutorial-series/tutorial10.md

@@ -1,4 +1,4 @@
-# 10 - Configuring RIP Routing in Cisco Packet Tracer
+# 10 - Configuring RIP Routing in Packet Tracer
 
 This tutorial is the ninth in our Cisco Packet Tracer series and introduces **dynamic routing** using the **Routing Information Protocol (RIP)**. Unlike static routes, RIP enables routers to exchange routing information automatically, making it easier to scale and manage networks with multiple paths.
 

cisco/tutorial-series/tutorial11.md

@@ -1,4 +1,4 @@
-# 11 - Configuring OSPF Routing in Cisco Packet Tracer
+# 11 - Configuring OSPF Routing in Packet Tracer
 
 This tutorial is the eleventh in our Cisco Packet Tracer series and focuses on **OSPF (Open Shortest Path First)**, a **link-state dynamic routing** protocol. Unlike RIP, OSPF supports larger networks, faster convergence, and more efficient routing decisions using cost metrics based on bandwidth.
 

cisco/tutorial-series/tutorial12.md

@@ -1,4 +1,4 @@
-# 12 - Configuring EIGRP Routing in Cisco Packet Tracer
+# 12 - Configuring EIGRP Routing in Packet Tracer
 
 This tutorial is the twelfth in our Cisco Packet Tracer series and focuses on **EIGRP (Enhanced Interior Gateway Routing Protocol)**, a **hybrid dynamic routing** protocol developed by Cisco. Unlike RIP, EIGRP supports larger networks, faster convergence, and uses composite metrics based on bandwidth and delay to make routing decisions.
 

cisco/tutorial-series/tutorial13.md

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+# 13 – Configuring a Default Route (Gateway of Last Resort)
+
+This tutorial is the thirteenth in our Cisco Packet Tracer series and focuses on **default routing**—also known as configuring a **gateway of last resort**. This type of route is essential in smaller or **stub networks**, where routers only have one exit path for unknown destinations.
+
+We will build a small branch-office style topology and configure the branch router to forward all unknown traffic to a main router using a static default route.
+
+---
+
+## Part 1 – Network Topology Overview
+
+This network includes:
+
+* **Two routers** (R0 = Branch, R1 = Main)
+* **One switch per router** (S0, S1)
+* **Two PCs per switch** (4 total PCs)
+
+The branch site will have no knowledge of external networks, so it will use R1 as its **gateway of last resort**.
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig1.png)
+
+---
+
+## Part 2 – Device Placement and Cabling
+
+### Step 2.1 – Add Devices to the Workspace
+
+From **Network Devices** and **End Devices**, place:
+
+* **2 Routers** (Router-PT-Empty)
+* **2 Switches** (2960)
+* **4 PCs**
+
+Label the devices:
+
+* Routers: **R0** (Branch), **R1** (Main)
+* Switches: **S0** (for R0), **S1** (for R1)
+* PCs: **PC0–PC3**
+
+### Step 2.2 – Add Network Modules to Routers
+
+Add:
+
+* **1x PT-ROUTER-NM-1S**
+* **1x PT-ROUTER-NM-1CFE**
+
+Turn off each router, insert modules, then power back on.
+
+If you need help with this, refer to the steps in [How to Customise the Router-PT in Packet Tracer](../handy-tips/tip5.md)
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig1.png)
+
+### Step 2.3 – Cabling
+
+Use **Copper Straight-Through** for PC to switch and switch to router connections. Use **Serial DCE** for the R0 ↔ R1 link.
+
+| From | To | Port/Interface |
+| ---- | -- | -------------- |
+| PC0  | S0 | fa0/1          |
+| PC1  | S0 | fa0/2          |
+| S0   | R0 | fa0/24 → fa2/0 |
+| PC2  | S1 | fa0/1          |
+| PC3  | S1 | fa0/2          |
+| S1   | R1 | fa0/24 → fa2/0 |
+| R0   | R1 | se0/0 ↔ se0/0  |
+
+---
+
+## Part 3 – IP Addressing Scheme
+
+Now we will assign IP addresses to all devices, ensuring they can communicate across the network.
+
+### Subnet Allocation
+
+For this tutorial, we will use the following subnets:
+
+| Subnet          | Devices      | Subnet Mask   |
+| --------------- | ------------ | ------------- |
+| 192.168.10.0/24 | PC0, PC1, R0 | 255.255.255.0 |
+| 192.168.20.0/24 | PC2, PC3, R1 | 255.255.255.0 |
+| 10.0.0.0/30     | R0 ↔ R1      | 255.0.0.0     |
+
+### Assign IPs to PCs
+
+Go to **Desktop > IP Configuration** on each PC:
+
+| PC  | IP Address   | Subnet Mask   | Default Gateway |
+| --- | ------------ | ------------- | --------------- |
+| PC0 | 192.168.10.11 | 255.255.255.0 | 192.168.10.1     |
+| PC1 | 192.168.10.12 | 255.255.255.0 | 192.168.10.1     |
+| PC2 | 192.168.20.13 | 255.255.255.0 | 192.168.20.1     |
+| PC3 | 192.168.20.14 | 255.255.255.0 | 192.168.20.1     |
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig3.png)
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig4.png)
+
+---
+
+## Part 4 – Router Configuration
+
+In this part, we will configure the routers to enable communication between the PCs and set up a default route on R0.
+
+```{admonition} Note
+:class: note
+To ensure all unknown traffic from the branch site is forwarded to the main router, we configure a default route on R0. This is done with the command `ip route 0.0.0.0 0.0.0.0 10.0.0.2`, which instructs R0 to send any traffic destined for networks it doesn't know about to R1. On R1, we add a static route pointing back to the branch network, allowing two-way communication.
+```
+
+### Step 4.1 – R0 (Branch Router)
+
+```bash
+enable
+configure terminal
+hostname R0
+
+interface fa1/0
+ip address 192.168.10.1 255.255.255.0
+no shutdown
+exit
+
+interface se0/0
+ip address 10.0.0.1 255.0.0.0
+clock rate 64000
+no shutdown
+exit
+
+ip route 0.0.0.0 0.0.0.0 10.0.0.2
+exit
+write memory
+```
+
+> This is the **default route**. It says: "Send all unknown traffic to `10.0.0.2` (R1)."
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig5.png)
+
+### Step 4.2 – R1 (Main Router)
+
+```bash
+enable
+configure terminal
+hostname R1
+
+interface fa1/0
+ip address 192.168.20.1 255.255.255.0
+no shutdown
+exit
+
+interface se0/0
+ip address 10.0.0.2 255.0.0.0
+no shutdown
+exit
+
+ip route 192.168.10.0 255.255.255.0 10.0.0.1
+exit
+write memory
+```
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig6.png)
+
+---
+
+## Part 5 – Verification and Testing
+
+### Step 5.1 – Check Routing Tables
+
+On **R0**:
+
+```bash
+show ip route
+```
+
+You should see a route labeled with `S*` – this is the static default route.
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig7.png)
+
+On **R1**:
+
+```bash
+show ip route
+```
+
+You should see a static route to `192.168.10.0` via `10.0.0.1`
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig8.png)
+
+### Step 5.2 – Ping Tests
+
+From **PC0**, try:
+
+```bash
+ping 192.168.20.10
+ping 192.168.20.13
+```
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig9.png)
+
+From **PC3**, try:
+
+```bash
+ping 192.168.20.13
+ping 192.168.10.11
+```
+
+![Figure](../../img/cisco-tutorials/tutorial-13/fig10.png)
+
+---
+
+## Summary
+
+In this tutorial, you:
+
+* Created a simple two-router topology
+* Assigned IP addresses and connected all devices
+* Configured a **default route** on the branch router
+* Verified full connectivity using `ping` and `show ip route`
+
+Default routes are vital in small or remote networks where only one path leads to the rest of the network or the internet.

cisco/tutorial-series/tutorial14.md

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+# 14

cisco/tutorial-series/tutorial3.md

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-# 3 – Exploring Simulation Mode in Cisco Packet Tracer
+# 3 – Exploring Simulation Mode in Packet Tracer
 
 This tutorial continues from where we left off in [Tutorial 2](../tutorial-series/tutorial2). You’ve successfully connected two PCs through two switches, now it’s time to **see how the data actually travels** using **Simulation Mode** in Cisco Packet Tracer.
 

cisco/tutorial-series/tutorial5.md

@@ -1,4 +1,4 @@
-# 5 – Understanding ARP in Cisco Packet Tracer
+# 5 – Understanding ARP in Packet Tracer
 
 This tutorial builds upon [**Tutorial 4 – Inter-VLAN Routing**](../tutorial-series/tutorial4) and focuses on a key Layer 2 concept: the **Address Resolution Protocol (ARP)**. ARP is essential for devices to communicate within a local network by resolving IP addresses to MAC addresses.
 

cisco/tutorial-series/tutorial6.md

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-# 6 – Understanding MAC Addresses in Cisco Packet Tracer
+# 6 – Understanding MAC Addresses in Packet Tracer
 
 This tutorial builds upon [**Tutorial 5 – Understanding ARP**](../tutorial-series/tutorial5) and explores how **MAC (Media Access Control) addresses** work in a switched network. MAC addresses are essential for Ethernet communication and play a key role in how switches forward frames.