Engineer. I measure what technology saves - and notice what it costs.https://dmitrygolovach.com/https://dmitrygolovach.com/posts/bgp-for-evpn/https://dmitrygolovach.com/posts/bgp-for-evpn/How BGP carries EVPN routes using Type 2 and Type 3 advertisements, and why even a perfect control plane depends on a healthy underlay.Wed, 22 Jul 2026 12:00:00 GMThttps://dmitrygolovach.com/posts/why-does-evpnvxlan-exist/https://dmitrygolovach.com/posts/why-does-evpnvxlan-exist/EVPN/VXLAN didn't appear because engineers wanted more acronyms. It appeared because the old network model broke under the demands of modern data centers.Mon, 20 Jul 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/when-automating-triage-quietly-costs-you-money/https://dmitrygolovach.com/posts/when-automating-triage-quietly-costs-you-money/I measured AI triage on 1500 closed GitHub issues across three real codebases. The cost case is real. But on one repo, automating would have silently mislabeled one issue in three — and the accuracy number gives you no warning.Mon, 22 Jun 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/ai-lower-cost/https://dmitrygolovach.com/posts/ai-lower-cost/We keep asking which jobs AI will replace. Maybe the better question is whether AI can lower the cost of changing direction — and make starting over survivable.Wed, 20 May 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/whose-walk-is-it/https://dmitrygolovach.com/posts/whose-walk-is-it/We used to walk without a destination. Now we walk 10,000 steps to close a ring. The walk is the same. But something is different.Mon, 18 May 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/live-in-present-feel-in-past/https://dmitrygolovach.com/posts/live-in-present-feel-in-past/We live in the present, but somehow feel somewhere else — in a past that's gone or a future that won't come. The aftertaste of a life that almost was never fully disappears.Tue, 05 May 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/cost-of-changing-life/https://dmitrygolovach.com/posts/cost-of-changing-life/You have a family, a mortgage, obligations. But what would it actually cost you to change direction? Maybe the problem isn't income — it's the structural risk of being wrong.Sun, 03 May 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/the-knowing/https://dmitrygolovach.com/posts/the-knowing/At the gym I saw teenage boys loud in the hot tub and a quiet man alone in the cold plunge. The strange thing about growing up is you can't see it from the inside — only in mirrors you didn't look for.Fri, 01 May 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/aws-well-architecture-framework/https://dmitrygolovach.com/posts/aws-well-architecture-framework/The AWS Well-Architected Framework is basically AWS handing you a checklist so you don't forget the important details. A walkthrough of all six pillars with practical exam tips.Thu, 08 Jan 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/swappable-llm-architectures/https://dmitrygolovach.com/posts/swappable-llm-architectures/Building applications tightly coupled to a single LLM provider creates technical debt. Here's an interface-based architecture pattern that lets you switch providers without rewriting your codebase.Mon, 05 Jan 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/automation-ai-workflows-ai-agents/https://dmitrygolovach.com/posts/automation-ai-workflows-ai-agents/Automation, AI Workflows, and AI Agents are often used interchangeably — but they represent fundamentally different levels of autonomy. A clear breakdown to help you choose the right approach.Sat, 03 Jan 2026 00:00:00 GMThttps://dmitrygolovach.com/posts/jenkins_installation/https://dmitrygolovach.com/posts/jenkins_installation/How to install Jenkins using Docker — pulling the image, running the container, and completing initial setup.Fri, 25 Nov 2022 00:00:00 GMThttps://dmitrygolovach.com/posts/go-meets-cisco-using-ssh/https://dmitrygolovach.com/posts/go-meets-cisco-using-ssh/Using Go to connect to Cisco devices over SSH — reading show commands programmatically and parsing network device output.Wed, 06 Jul 2022 00:00:00 GMThttps://dmitrygolovach.com/posts/postman-environment-variables/https://dmitrygolovach.com/posts/postman-environment-variables/Using Postman Environment Variables to manage tokens and base URLs across collections — making API testing much easier.Thu, 03 Feb 2022 00:00:00 GMThttps://dmitrygolovach.com/posts/python-script-structure/https://dmitrygolovach.com/posts/python-script-structure/Basic Python script structure notes — a reference for organizing scripts with imports, functions, and a main entry point.Tue, 31 Dec 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vxlan-and-external-connectivity/https://dmitrygolovach.com/posts/cisco-nx-os-vxlan-and-external-connectivity/How to connect VXLAN fabrics to the outside world — external routing, VRF leaking, and border leaf design.Thu, 05 Dec 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vxlan-vpc-anycast/https://dmitrygolovach.com/posts/cisco-nx-os-vxlan-vpc-anycast/The problem with VXLAN and vPC — and how anycast VTEP solves it by presenting a single logical VTEP address.Tue, 03 Dec 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vxlan-symmetric-routing/https://dmitrygolovach.com/posts/cisco-nx-os-vxlan-symmetric-routing/EVPN IRB symmetric routing: how it solves the ARP/CAM scaling problems of asymmetric routing using L3 VNIs.Tue, 26 Nov 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vxlan-asymmetric-routing/https://dmitrygolovach.com/posts/cisco-nx-os-vxlan-asymmetric-routing/EVPN IRB asymmetric routing: how it works, its limitations with ARP cache and CAM table scaling, and when to avoid it.Thu, 21 Nov 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vxlan-bgp-evpn-control-plane/https://dmitrygolovach.com/posts/cisco-nx-os-vxlan-bgp-evpn-control-plane/BGP EVPN as a control plane for VXLAN: route types, MP-BGP, and how it replaces flood-and-learn.Tue, 19 Nov 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vxlan-configuration/https://dmitrygolovach.com/posts/cisco-nx-os-vxlan-configuration/Configuring VXLAN with multicast flood-and-learn control plane on Cisco NX-OS. Step-by-step with commands.Thu, 14 Nov 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-ns-os-virtual-extensible-lan-vxlan-overview/https://dmitrygolovach.com/posts/cisco-ns-os-virtual-extensible-lan-vxlan-overview/VXLAN is a tunneling protocol that encapsulates Layer 2 Ethernet frames in Layer 3 UDP packets. An overview of how it works and why it exists.Tue, 12 Nov 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-fabricpath-fp/https://dmitrygolovach.com/posts/cisco-nx-os-fabricpath-fp/FabricPath is Cisco's L2 routing technology — MAC-in-MAC routing that removes STP from the topology. How it works and when to use it.Thu, 31 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vpc-failures/https://dmitrygolovach.com/posts/cisco-nx-os-vpc-failures/How vPC handles failures: orphan ports, peer link loss, keepalive loss, and dual-active scenarios.Tue, 29 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vpc-fhrp/https://dmitrygolovach.com/posts/cisco-nx-os-vpc-fhrp/FHRP acts as active/active forwarding over vPC. How HSRP and VRRP integrate with vPC on Nexus switches.Thu, 24 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-from-vpc-to-back-to-back-vpc/https://dmitrygolovach.com/posts/cisco-nx-os-from-vpc-to-back-to-back-vpc/The vPC Peer Link should never be blocking. Notes on moving from standard vPC to back-to-back vPC topologies.Tue, 22 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-vpc-configuration/https://dmitrygolovach.com/posts/cisco-nx-os-vpc-configuration/Step-by-step vPC configuration on Cisco NX-OS: peer keepalive, peer link, vPC domain, and member ports.Thu, 17 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-virtual-port-channel-vpc/https://dmitrygolovach.com/posts/cisco-nx-os-virtual-port-channel-vpc/Multi-Chassis EtherChannel types and vPC fundamentals. The building blocks of vPC on Cisco Nexus switches.Tue, 15 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-fabric-extender-fex/https://dmitrygolovach.com/posts/cisco-nx-os-fabric-extender-fex/Nexus 2000 Fabric Extenders act as remote line cards. Notes on FEX architecture, connectivity modes, and design considerations.Tue, 08 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-nexus-virtual-device-contexts-vdcs/https://dmitrygolovach.com/posts/cisco-nx-os-nexus-virtual-device-contexts-vdcs/Nexus Virtual Device Contexts let you virtualize physical hardware — similar to contexts in ASA. How VDCs work on Cisco Nexus.Thu, 03 Oct 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-nx-os-cli-notes/https://dmitrygolovach.com/posts/cisco-nx-os-cli-notes/Practical NX-OS CLI notes: aliases, show commands, and tips for working efficiently on Cisco Nexus switches.Mon, 30 Sep 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/python-simple-email-gmail/https://dmitrygolovach.com/posts/python-simple-email-gmail/A Python script that sends email notifications from a Gmail account — useful for scripts that need to report status or data.Tue, 24 Sep 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-sd-wan-zero-touch-site-bring-up/https://dmitrygolovach.com/posts/cisco-sd-wan-zero-touch-site-bring-up/Cisco SD-WAN zero-touch provisioning (ZTP): how Viptela's automatic provisioning SaaS brings up new sites without on-site engineers.Fri, 26 Apr 2019 00:00:00 GMThttps://dmitrygolovach.com/posts/cisco-sd-wan-basic-overview/https://dmitrygolovach.com/posts/cisco-sd-wan-basic-overview/Key components of Cisco SD-WAN: vManage, vSmart, vBond, and vEdge. An overview of the architecture and control plane.Mon, 15 Apr 2019 00:00:00 GMT