Networking skills
employers want

Networking fundamentals are how devices find and talk to each other. The core topics are the OSI and TCP/IP models; IPv4 and IPv6 addressing, subnet masks and CIDR; DHCP for automatic addressing; DNS for name resolution; switching, MAC addresses and VLANs; routing and default gateways; NAT; TCP versus UDP and common ports; Wi-Fi standards and security; VPNs; and troubleshooting tools such as ping, traceroute, nslookup or dig, and packet capture.

IPv6 is now mainstream. Google's statistics show 49.6% of users reaching Google over IPv6 as of late October 2026.¹ Networks are also a frequent attack path: Verizon's 2026 DBIR found exploited vulnerabilities, often in edge devices, are now the top way into breaches.² Networking is a large employer in India — AmbitionBox lists network engineers at a typical ₹4.9–5.5 lakh from more than 62,000 salaries, up 13% in two years.³ In the US, computer network architects earn a $134,050 median with 8% growth to 2035,⁴ while network and computer systems administrator jobs are projected to shrink slightly as work moves to the cloud.⁵

Users reaching Google over IPv6 (Google, Oct 2026)

49.6%

Typical network engineer pay in India (AmbitionBox)

₹4.9–5.5 lakh

Network engineer salaries reported in India (AmbitionBox)

62,000+

US median, network architects (BLS, May 2025)

$134,050

Table: How networking skills are assessed (editorial summary)

Table: Splitting 192.168.10.0/24 into subnets (worked example)

Table: How networking developed (editorial summary)

• Subnetting practice with correct answers
• A home or virtual lab network
• DNS and DHCP configured
• A packet capture you analysed
• A troubleshooting write-up
• A verified networking fundamentals certificate

Show troubleshooting and design: "Designed VLAN and subnet plan for 150-user office; resolved recurring DNS outages; documented network diagrams."

"What happens when you type a URL into a browser?"

DNS lookup, TCP (and TLS) connection, HTTP request and response, rendering — with each layer involved.

"TCP vs UDP?"

TCP is connection-oriented and reliable; UDP is connectionless and faster, used for DNS queries, streaming and gaming.

"How do you troubleshoot no internet?"

Check link, IP configuration, gateway, DNS and then wider routing — bottom up.

"What's a VLAN?"

A logical network segment on shared switches, separating traffic.

"How many usable hosts in a /26?"

62.

• "What's the network size and sites?" — scope.
• "Which vendors and tools?" — skills.
• "Is IPv6 deployed?" — modernity.
• "How much is cloud networking?" — direction.

Table: Network roles and typical pay in India (AmbitionBox, October 2026; indicative)

Table: Common networking tools (editorial guidance)

• IT support — basic network troubleshooting.
• Network engineer — operations and configuration.
• Senior network engineer — design.
• Network architect / cloud networking — architecture.
• Network security or SRE — specialisation.

1. Week 1: Concepts — Models, addressing, subnetting drills.
2. Week 2: Services — DNS, DHCP, routing in a lab.
3. Week 3: Prove it — Troubleshoot scenarios; take the Networking Fundamentals Certification.

Next: Network Security, IT Support and Cloud Computing. Guides: network security, IT support and cloud computing.

• Troubleshooting — connectivity issues.
• Changes — VLANs, routes, firewall requests.
• Monitoring — uptime and bandwidth.
• Documentation — diagrams and IP plans.
• Upgrades — firmware and hardware.
• Security — access and segmentation.

"What is NAT?"

Network address translation — mapping private addresses to public ones.

"What's a default gateway?"

The router a device sends traffic to when the destination isn't on its local network.

Table: A first-90-days plan (editorial guidance)

Learn the network's layout and documentation first; update diagrams if they're stale. Handle routine changes carefully with rollback plans. By the third month, fix the root cause of a recurring problem.

AI-driven network monitoring now detects anomalies, predicts failures and suggests fixes, and assistants can explain configurations or generate commands. Networks are increasingly managed as code and through cloud consoles rather than device-by-device. These tools help, but engineers still need to understand what a configuration does before applying it — a wrong route or ACL can take down a site. Fundamentals let you verify AI suggestions and troubleshoot when tools disagree.

Use free simulators or virtual machines to build a small network with two subnets, a router, a DHCP server and a DNS server. Add a VLAN and a firewall rule. Then break things deliberately — wrong gateway, missing DNS record, overlapping subnet — and diagnose them with ping, traceroute, dig and packet captures. Document each scenario. This practice turns theory into troubleshooting instinct.

Memorise the block sizes for common prefixes (/24 = 256 addresses, /25 = 128, /26 = 64, /27 = 32, /28 = 16), remember usable hosts are two fewer in IPv4, and practise ten problems a day for a week. Speed comes from repetition, and interviewers notice confident, quick answers.

"Cloud means networking doesn't matter." Cloud networks still need subnets, routes, DNS and security.

"It's just plugging in cables." Modern networking is design, automation and security.

"IPv6 can wait." Half of users already use it.

When you type a website name, your device first checks its local cache. If the answer isn't there, it asks a recursive resolver, usually provided by your ISP, company network or a public DNS service. The resolver, if it doesn't have a cached answer, asks a root server, which points it to the servers for the top-level domain such as .com or .in. Those point to the domain's authoritative name servers, which finally return the IP address. The resolver caches the answer for the time-to-live set on the record and returns it to your device.

Understanding this chain helps troubleshooting enormously. If one device can't resolve a name but others can, the problem may be its local cache or configured resolver. If nobody can resolve an internal name, the internal DNS server or its records may be wrong. If changes don't seem to take effect, cached records with long TTLs may still be in use. Tools like dig and nslookup let you query specific servers and see which one gives which answer.

Common record types are worth knowing: A and AAAA records map names to IPv4 and IPv6 addresses, CNAME records alias one name to another, MX records route email, TXT records carry verification and email security data, and NS records delegate zones. Many outages blamed on "the network" are actually DNS mistakes — a deleted record, an expired domain or a wrong TTL during a migration.

When a device joins a network, DHCP gives it an IP address, subnet mask, default gateway and DNS servers. The subnet mask tells the device which addresses are local. For anything outside that range, the device sends traffic to the default gateway, usually a router, which forwards it onward. A wrong gateway or DNS setting from DHCP can make a device appear online but unable to reach the internet or internal services. Checking the IP configuration is therefore one of the first steps in troubleshooting.

• Weak subnetting.
• Ignoring DNS.
• Random rebooting instead of diagnosis.
• No lab practice.
• Undocumented changes.

IPv6 adoption comes from Google's statistics (October 2026); India pay from AmbitionBox (read October 2026); US pay and outlook from the Bureau of Labor Statistics (May 2025); and threat trends from Verizon's 2026 DBIR. The subnetting example, lab guidance and history are editorial. Science of Apps publishes the free test linked here. Last reviewed October 2026.

• IP address — a device's network address.
• Subnet — a smaller network within a larger one.
• DNS — the system mapping names to IP addresses.
• DHCP — automatic IP address assignment.
• VLAN — a virtual network segment.