A static route on a Cisco router can be written two ways: with a next-hop IP address, or with an exit interface. The two forms LOOK almost identical in the running-config but they cause different forwarding behavior, different
ARP - the Address Resolution Protocol - is the unsung mechanism that makes Layer 3 routing actually work over Layer 2 Ethernet. Every time your router forwards a packet on a LAN, ARP is what tells it which MAC address to write
IPv6 has been "the new thing" for so long that engineers sometimes forget it is now the default address family on cloud platforms, mobile networks, and most modern ISPs. This lab teaches the structure of an IPv6 address:
The IOS XE command-line interface is the language you will type into every Cisco router in this library. Hundreds of commands, dozens of modes, one set of conventions that everyone in networking takes for granted but no one is
Standard access lists filter traffic based on source IP only. Numbered standard ACLs use IDs 1-99 and 1300-1999. They are the simplest filter on a Cisco router and a great introduction to the ACL concept: a list of
OSPF (Open Shortest Path First) is the link-state protocol that powers most enterprise networks. Single-area OSPF puts every router in Area 0 - the backbone - and is the simplest production-grade dynamic routing protocol you can deploy. This lab
VLANs work fine on a single switch. The minute you have two switches and want VLAN 10 on both, you need a trunk: a port that carries traffic for multiple VLANs and tags each frame with its VLAN ID so
Variable-Length Subnet Masking is the skill that turns a CCNA candidate into someone who can stand at a whiteboard with five rectangles and turn them into a working network. The math is not complex. The discipline is. This lab
This is the first lab in the PingLabz CCNA Labs library. There is no networking in it. The goal is to get Cisco Modeling Labs Free installed on your computer, import the PingLabz CCNA Base Topology, boot it, and log
Cisco ASA has a lot of moving parts. Three NAT sections that evaluate in a non-obvious order. ACLs that reference real or pre-NAT IPs (post-8.3) instead of the public ones you remember. A packet pipeline that
If you are managing Cisco ASA hardware in 2026, you are managing inherited gear. Cisco's strategic firewall is now Secure Firewall Threat Defense (FTD, formerly known as Firepower Threat Defense). The platform is not just a UI rebrand:
Multiple context mode turns a single Cisco ASA into a hypervisor for several virtual firewalls. Each context has its own configuration, interfaces, ACLs, NAT rules, routing table, and even its own administrators. The classic use cases are service providers (one