Jeremy's IT Lab - Basic OSPF Configurations

Introduction

• Jeremy's IT Lab offers a free, complete CCNA course.
• Subscribing, liking, commenting, and sharing the video supports the series.
• Lab files are available via a link in the video description for practice with packet tracer.
• Boson's NetSim is recommended for additional labs and practice.

Lab Overview

• The lab involves basic OSPF configurations in a small network.
• Steps include configuring loopback interfaces and OSPF on routers R1 to R4.

Pre-Lab Configuration

• Hostnames and IP addresses are assumed to be pre-configured.
• Loopback interfaces are virtual and provide stable connectivity.

OSPF Configuration Steps

Step 2: Loopback Interface Configuration

• Configure loopback interfaces on all routers.
  • Example for R4: INTERFACE L0 -> IP ADDRESS 4.4.4.4 255.255.255.255
• Verify loopback configuration using:
  • DO SHOW IP INTERFACE BRIEF
  • DO SHOW INTERFACE L0 to ensure correct subnet mask.

Step 3: OSPF Configuration

• Use different OSPF process IDs on each router.
• Enable OSPF on interfaces:
  • Use NETWORK 0.0.0.0 255.255.255.255 AREA 0 for all interfaces.
  • Be specific in real networks about which interfaces activate OSPF.
• Configure passive interfaces:
  • F1/0 and F2/0 active, G0/0 and L0 passive on R4.
  • Similar steps for R3, R2, and R1 with respective IP addresses.

Configuring Default Route on R1

• Use DEFAULT-INFORMATION ORIGINATE to advertise a default route.
• Configure the default route: IP ROUTE 0.0.0.0 0.0.0.0 203.0.113.2.

OSPF Verification and Commands

• Use SHOW IP PROTOCOLS to verify router ID and ASBR status.
• Check OSPF database with SHOW IP OSPF DATABASE.
• View OSPF neighbors with SHOW IP OSPF NEIGHBOR.
• Check interface-specific OSPF settings with SHOW IP OSPF INTERFACE.

Routing Table Verification

• Verify default routes on R2, R3, and R4.
  • R2: Default route via 10.0.12.1 (R1).
  • R3: Default route via 10.0.13.1 (R1).
  • R4: Load-balances over R2 and R3 due to interface bandwidth.

Bonus Lab: Boson NetSim

• Preview of planning and configuring single-area OSPF lab.
• Lab tasks include verifying initial configurations and planning OSPF.
• Specific subnets and wildcard masks are used in NETWORK commands.

Conclusion

• Basic OSPF configurations and passive interfaces covered.
• Encourage exploring Boson NetSim labs for deeper understanding.
• Acknowledge channel supporters and encourage viewer engagement.