CompTIA Network+ prep
You study the Network+ exam topics hands-on with real Linux tools, from addressing and routing to services and monitoring.
Level 201 · 22 lessons · 21 practice labs
Lessons
Concepts and addressing
- Networking concepts and the OSI/TCP-IP models: You will be able to describe the roles of network devices and what happens at each layer of the OSI and TCP/IP models.
- A reference table of common ports and protocols: You will recall the ports of common services such as HTTP, SSH, DNS and SMTP, and their TCP or UDP use, by logic.
- IP addressing and subnetting: You will learn to read IP addresses, split a network into subnets and work out how many devices fit in each.
- Unicast, multicast and broadcast addresses; reachability tests: You will explain the three address types and test with ping which addresses on a subnet are reachable.
- DNS records for IPv6 and transition tunnels from IPv4: You will query an AAAA record and explain what a tunnel is for during the move to IPv6.
- Short task: draw up an IPv4 and IPv6 address plan for a four-department office
Switching, routing and wireless
- Ethernet links, cabling and checking interfaces with ethtool: You will recognise cable types and speed-duplex mismatches and read an interface’s real link speed with ethtool.
- ARP and neighbour tables: reading local-network mappings: You will read which IP maps to which MAC address in ip neigh and arp output and notice inconsistencies.
- Switching and VLANs: You will understand how switches forward traffic and how VLANs separate one network into logical parts.
- Link aggregation (bonding) for redundancy and speed: You will combine two interfaces in a bond and test that access continues when one link fails.
- Routing: You will understand how routers decide where to send packets, and the difference between static and dynamic routing.
- Wireless networks: You will be able to explain wireless standards, channels and why wireless security settings matter.
- Cloud and virtualisation networking: You will understand how virtual and cloud networking concepts differ from physical networks and what stays the same.
- Short task: separate two VLANs and allow only the traffic they need between them
Services, security and operations
- Network services: DNS, DHCP, NTP: You will understand what DNS, DHCP and NTP each do on a network and what symptoms appear when they fail.
- Setting up an authoritative DNS server and a zone file: You will write a simple zone file for your own domain and verify an authoritative answer with dig.
- Network security: You will tell apart the roles of network defences such as firewalls, access control and intrusion detection tools.
- Secure network device monitoring with SNMPv3: You will define an SNMPv3 user and read a device’s status through an authenticated, encrypted query.
- Monitoring and troubleshooting: You will learn network monitoring tools and a step-by-step, layer-by-layer method for finding and fixing network problems.
- Short task: run a DNS server for your own domain and put it under monitoring
Exam preparation
- Exam strategy and practice questions: You will recognise exam question patterns, learn to manage your time and use practice questions to see which areas need work.
- Capstone: build a branch network, secure it and fix its faults
Practice labs
- Split a /24 into four equal subnets: You split Gelincik Fırın's single /24 into equal subnets for four branches and tabulate each one's network, broadcast and first and last addresses.
- Find the subnet with the wrong mask: You compare six clients' address settings, prove that the one unable to reach its gateway has the wrong mask and fix it.
- Build a tight address plan with variable masks: You draw a gap-free VLSM plan from one /24 for segments of 120, 50, 25 and 2 devices and apply it on the lab router.
- Tell IPv6 address types apart: You tell apart the link-local, global unicast and multicast IPv6 addresses on a server and write each one's purpose.
- Move a client to dual stack: You give a client a static IPv6 address and gateway and verify it reaches the server over both IPv4 and IPv6.
- Solve a site that fails while it has an AAAA record: You find why an internal site with an AAAA record but a broken IPv6 path loads slowly and fix the path or the record.
- Read an interface's speed and duplex: You read the link state, speed and duplex of a server's interfaces with ethtool and report them.
- Fix a connection broken by a stale ARP entry: You find in the neighbour table why a server whose IP was reassigned is unreachable and clear the entry.
- Find two devices sharing one IP: You prove with ARP entries and MAC addresses that another device is using an intermittently dropping printer's address and resolve the conflict.
- Add a tagged VLAN interface to a server: You create a tagged sub-interface for VLAN 30 on a Linux server and reach the gateway on that VLAN.
- Move a PC that landed in the wrong VLAN: You find from the bridge configuration that a client unable to reach accounting is on the guest VLAN and move it to the right one.
- Allow only printer traffic between VLANs: You route between two VLANs, allow only printing ports and test that all other traffic is blocked.
- Find which leg of a bond is active: You read a server's bond mode and active link from /proc/net/bonding and report them.
- Test failover on a redundant link: You join two interfaces in active-backup mode and prove with a continuous ping that connectivity survives shutting one down.
- Fix a bond in the wrong mode: You switch a bond set to round-robin without switch support, which drops packets, to a suitable mode and measure that the loss stops.
- List a domain's records: You query a domain's A, MX, NS and TXT records from the lab DNS server with dig and put them in a table.
- Add a new server to a zone file: You add a new server's A and PTR records to the authoritative zone, bump the serial and verify resolution in both directions.
- Repair a secondary DNS that stopped updating: You find in the serial number and transfer permissions why changes on the primary no longer reach the secondary and fix it.
- Read a device's interface counters over SNMP: You pull interface names and traffic counters from the lab router over SNMP and find the busiest interface.
- Replace a community string with an SNMPv3 user: You close an agent left open with a default community string and keep monitoring through an authenticated, encrypted SNMPv3 user.
- Set a threshold alert for link utilisation: You write a script that computes five-minute utilisation from SNMP counters and test that it logs an alert above 80 per cent.
About this course
You study the Network+ exam topics hands-on with real Linux tools, from addressing and routing to services and monitoring.
What you will learn
- Concepts and addressing
- Switching, routing and wireless
- Services, security and operations
- Exam preparation
Prerequisites
Finishing the level 101 courses of the same path, or knowing those topics, is enough.
Lab environment
Lessons run in your own Kali Linux terminal in the browser, connected to a private lab network. Nothing to install.
Frequently asked questions
- Is this course right for my level?
- The course is at level 201; it assumes you know the topics of the lower-level courses.
- Is there anything to install?
- No. Every lesson runs in your own lab environment that opens in the browser.
- How do lessons work?
- Each lesson has 8 to 10 steps and a short quiz. Early steps show the command to type, later steps give less help; if two attempts fail, the solution opens.
- Can I try it for free?
- Yes. The first three lessons of every course are free.