Network Engineer: The Infrastructure Role That Predates the Internet and Outlasted Every Prediction of Its Demise

Every other infrastructure role in this series was created by the internet era. Network Engineering predates it. The discipline of designing, building, and maintaining the systems that carry data between computers is older than the World Wide Web, older than the commercial internet, and — despite periodic predictions that cloud and software-defined networking would make it obsolete — continues to employ hundreds of thousands of people globally and remains one of the most essential technical functions in any organisation that depends on connectivity. Which is all of them. ## The Foundation: What Network Engineers Actually Work With To understand Network Engineering as a profession, it helps to understand the technology underlying it. TCP/IP — the Transmission Control Protocol and Internet Protocol that define how data moves across interconnected networks — was standardised in 1981. RFC 791 (IP) and RFC 793 (TCP) are the foundational specifications. They were designed to be resilient and decentralised, and they have proven durable beyond what their creators could have anticipated: the same fundamental protocols that carried email between university research departments in 1981 carry video calls, streaming media, financial transactions, and AI model inference today. BGP — the Border Gateway Protocol — is the routing protocol that ties the global internet together. It is how the roughly 900,000 distinct network routes on the internet (as of 2024) are advertised and exchanged between the approximately 75,000 autonomous systems (networks operated by ISPs, universities, corporations, and governments) that collectively constitute the internet. BGP was standardised in RFC 4271 in 2006, though earlier versions date to 1989. When BGP is misconfigured, significant portions of the internet can become unreachable — the 2010 incident in which China Telecom accidentally advertised routing paths that caused traffic from US government and military sites to route through China, and the 2021 Facebook outage in which an internal BGP configuration change made Facebook, Instagram, and WhatsApp globally unreachable for six hours, both illustrate how consequential BGP configuration is. LAN (Local Area Network) networking within organisations runs primarily on Ethernet (standardised by IEEE 802.3) and Wi-Fi (IEEE 802.11). Network Engineers design, deploy, and maintain the switches, wireless access points, and cabling that constitute internal network infrastructure. ## The Role of Cisco No discussion of Network Engineering as a profession is complete without Cisco Systems. Founded in 1984 by Stanford computer scientists Len Bosack and Sandy Lerner, Cisco built the routers and switches that became the dominant networking hardware globally. Cisco's IOS (Internetwork Operating System) became the de facto standard for router and switch configuration — generations of network engineers learned networking by learning Cisco IOS command syntax. Cisco holds approximately 40% of the global enterprise networking hardware market as of 2024, despite significant competition from Juniper Networks, Arista Networks, and more recently from hyperscale cloud providers building their own networking infrastructure. Cisco's certification programme — from CCNA (Cisco Certified Network Associate) through CCNP (Cisco Certified Network Professional) to CCIE (Cisco Certified Internetwork Expert) — has been the gold standard of Network Engineering credentials for over 30 years. The CCIE, which requires passing a written exam followed by an eight-hour hands-on lab exam, is among the most demanding technical certifications in the industry and is held by fewer than 70,000 people worldwide. It remains a meaningful credential in hiring. ## How Network Engineering Is Changing The most significant transformation in Network Engineering since the field's inception is underway now: the shift from hardware-centric, manual configuration to software-defined, programmatically managed networking. **Software-Defined Networking (SDN)** separates the "control plane" — the logic that determines how traffic is routed — from the "data plane" — the hardware that actually moves packets. In traditional networking, both functions live in the same physical device (a router or switch). SDN centralises the control plane in a software controller, making network behaviour programmable and allowing policies to be changed without touching physical hardware. Google's B4 network, which carries traffic between Google's data centres, has been SDN-based since 2012. The same principles are now widespread in enterprise networking. **SD-WAN (Software-Defined Wide Area Network)** applies SDN principles to the links connecting branch offices and remote locations to corporate networks. IDC projects the SD-WAN market will reach $13.9 billion by 2027. Network Engineers who understand SD-WAN platforms (from Cisco, VMware, Fortinet, and others) are in demand as enterprises replace legacy MPLS circuits with SD-WAN. **Network Automation.** The Juniper Networks 2023 State of Network Automation Report found that 70% of network engineers were automating tasks they previously performed manually. Ansible — originally built for server configuration management — has extensive networking modules and has become a primary automation tool for network engineers. Python, combined with libraries like Netmiko (SSH-based device interaction) and NAPALM (unified API for multiple network OS types), enables programmatic management of network devices. Network engineers who can write Python automation scripts are consistently more employable and better-compensated than those who work only through CLI commands. **Cloud Networking.** AWS VPC (Virtual Private Cloud), Azure Virtual Network, and GCP VPC are software-defined networking environments that network engineers increasingly need to understand. Cloud networking involves subnets, security groups (stateful firewall rules), network ACLs, transit gateways, VPN connections, Direct Connect and ExpressRoute (dedicated private connections from on-premises to cloud), and load balancers — all of which are networking concepts, implemented as cloud services. Network engineers who extend their expertise into cloud networking can design and manage the connectivity between on-premises environments and cloud infrastructure — a critical function for virtually every enterprise in a hybrid cloud state. ## What Network Engineers Do Day to Day **Network design and architecture.** Planning the topology and capacity of networks — how many switches and routers, in what configuration, with what redundancy — is Network Engineering's strategic work. This requires understanding traffic patterns, failure modes, growth projections, and budget constraints. **Configuration and change management.** Implementing and modifying network device configurations, whether by CLI, automation scripts, or network management platforms. Change management is critical in networking because a misconfiguration can take an entire organisation offline — changes go through review, testing in lab environments, and controlled rollout processes. **Troubleshooting.** Network problems are among the most difficult infrastructure issues to diagnose because failures can originate at any layer — physical (a cable), data link (a switch port), network (a routing issue), transport (a firewall rule), or application (a misconfigured service). Network Engineers use packet capture tools (Wireshark is the universal standard), protocol analysers, and network monitoring platforms to diagnose problems systematically. **Security.** Firewalls, intrusion detection and prevention systems (IDS/IPS), network access control (NAC), and network segmentation (VLANs, security zones) are all Network Engineering responsibilities. The network is both the surface through which attacks arrive and the layer where many of them can be detected and blocked. ## The Job Market The Bureau of Labor Statistics places network and systems administrators at approximately 400,000 employed workers in the United States, with a median annual wage of $95,360 as of 2023. Network Engineering roles with cloud networking, automation, and security specialisations command significantly more — $120,000-$150,000 at the senior level. The AWS Advanced Networking Specialty certification validates cloud networking expertise and is valued alongside traditional Cisco credentials in hybrid-environment roles. Juniper's JNCIA/JNCIE certifications are respected in environments that use Juniper hardware. For network automation, demonstrable Python proficiency — GitHub repositories, open-source contributions, or portfolio projects — carries more weight than certifications in most hiring processes. The narrative that network engineering is declining due to cloud adoption has not materialised in the employment data. Cloud environments need networking expertise to design and manage. Hybrid environments — the state of most enterprises — need engineers who understand both traditional networking and cloud networking. Software-defined networking requires engineers who understand both the network principles and the automation tools that implement them. The network engineering skill set is expanding, not contracting.