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Network glossary
What Is ZTNA? Zero Trust Network Access
What is ZTNA? Zero Trust, core principles, comparison with VPN, SDP/Agent, and vendors including Zscaler and Palo Alto.
April 15, 2026
Technical resources
Original optics, documented by reference.
Buying guides, technical notes and manufacturer-reference resources for professional optical links.
Editorial scope
SFP through QSFP-DD · original manufacturer references · selection boundaries · procurement context
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Network glossary
What Is SASE? Secure Access Service Edge
What is SASE? Convergence of SD-WAN + ZTNA + SWG + CASB + FWaaS, vendors, and pricing.
April 15, 2026
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Network glossary
What Is SD-WAN? Software-Defined WAN Explained
What is SD-WAN? SLA-based path selection, multiple links, ZTP, vendors, and MPLS savings.
April 15, 2026
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Network glossary
What Is a Site-to-Site VPN? IPsec and Alternatives
What is a site-to-site VPN? IPsec, IKEv2, topologies, and 2026 algorithms explained.
April 15, 2026
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Network glossary
What Is EVPN? BGP as the Data Center Control Plane
What is EVPN? MP-BGP control plane, Type 1-5 routes, multi-homing, and data center applications.
April 15, 2026
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Network glossary
What Is VXLAN? Encapsulation and Operation
What is VXLAN? L2/L3 overlay, 16M VNIs, BGP EVPN, and spine-leaf data centers.
April 15, 2026
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Network glossary
What Is MPLS? Definition and Operation
What is MPLS? Label switching, L3VPN/L2VPN, Traffic Engineering, and comparison with SD-WAN.
April 15, 2026
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Network glossary
What Is a Router? Definition and Differences from a Switch
What is a router? Definition, OSPF/BGP routing protocols, router types, and differences from an L3 switch.
April 15, 2026
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Network glossary
What Is a Network Switch? Definition, Types, and Selection Guide
What is a network switch? Definition, L2/L3, managed/PoE, specifications, and brands.
April 15, 2026
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Network glossary
What Is a VLAN? Definition, Operation, and Configuration
What is a VLAN? 802.1Q definition, access/trunk modes, security, and VXLAN beyond 4094.
April 15, 2026
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Network glossary
What Is DNS? How the Domain Name System Works
What is DNS? Definition, hierarchy, records, resolution chain, DNSSEC, and DoT/DoH.
April 15, 2026
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Network glossary
What Is a Firewall? Definition, Operation, and Firewall Types
What is a firewall? Definition, types (NGFW, WAF), functions, and leading vendors in 2026.
April 15, 2026