This book contains CCNA Certification Exam 200-125 Step By Step Lab Exercises. The lab exercises can be performed either on the physical devices or on the simulators. However, arranging physical devices is certainly a difficult job. So we have designed this book for those self-learners who want to earn their CCNA certification and hands-on skills by self-study. In this lab guide, we have used Cisco Packet Tracer simulator to demonstrate all the step by step lab exercises. The instructions are mentioned in such as details that a candidate having just the basic knowledge of computer can easily perform all the mentioned lab exercises without requiring any help from a trainer/instructor/institute. This book consists of the following concepts and step by step lab exercises: Lab Exercise 01: Downloading Cisco Packet Tracer Lab Exercise 02: Creating a Topology in Cisco Packet Tracer Lab Exercise 03: Getting Started with Cisco IOS Lab Exercise 04: Basic Configuration of a Router Lab Exercise 05: Breaking Router Password Lab Exercise 06: Restore Cisco IOS from ROMMON Mode Concept 01: Basics of Routing Concept 02: The IP Routing Process – Step By Step Concept 03: Classful vs Classless Routing Protocol Lab Exercise 07: Configure Routing Lab Exercise 08: Configuring RIP Routing Lab Exercise 09: Configuring EIGRP Routing Lab Exercise 10: Configuring OSPF Routing Lab Exercise 11: Configuring OSPF Cost Metric Lab Exercise 12: Configuring IPX Routing Concept 04: Route Redistribution Basics Lab Exercise 13: Route Redistribution between RIP and EIGRP Lab Exercise 14: Route Redistribution between OSPF and RIP Lab Exercise 15: Route Redistribution between OSPF and EIGRP Lab Exercise 16: Implementing IPv6 Addressing Lab Exercise 17: Configuring RIP for IPv6 (RIPng) Lab Exercise 18: Configuring EIGRP for IPv6 (EIGRPv6) Lab Exercise 19: Configuring DHCP on Cisco Router Concept 05: Process of Building MAC Address Table Lab Exercise 20: Enabling Remote Access Lab Exercise 21: Configuring VLANs Lab Exercise 22: Configuring Inter-VLAN Routing Lab Exercise 23: Configuring Etherchannel Lab Exercise 24: Configuring Port Security Lab Exercise 25: Configuring Spanning-Tree Protocol Lab Exercise 26: Configuring Spanning-Tree PortFast Lab Exercise 27: Configuring Access Control Lists (ACLs) Lab Exercise 28: Configuring Static and Dynamic NAT Lab Exercise 29: Configuring Frame-Relay Lab Exercise 30: Configuring WAN authentication Lab Exercise 31: Configuring Redundancy using HSRP Lab Exercise 32: Configure Syslog Server