Sachin Kumar Sharma | Engineering Blog & War Stories

Sachin Kumar Sharma | Engineering Blog & War Stories Architectural patterns, war stories, and engineering philosophy across 20+ years of production cloud & AI operations. https://virtualsach.in/blog en-us Copyright 2026 Sachin Kumar Sharma 60 <![CDATA[The Seven Failure Modes of Autonomous AI Agent Systems (And How to Fix Them)]]> https://virtualsach.in/blog/2026-08-seven-failure-modes-agentic-systems https://virtualsach.in/blog/2026-08-seven-failure-modes-agentic-systems Sat, 01 Aug 2026 00:00:00 GMT <![CDATA[The Death of Cloud LLM Monopoly: Enterprise FinOps and Zero-Cost Client-Side AI]]> https://virtualsach.in/blog/2026-07-enterprise-finops-client-side-ai https://virtualsach.in/blog/2026-07-enterprise-finops-client-side-ai Mon, 20 Jul 2026 06:30:00 GMT <![CDATA[Browser-Side Agentic Engine Architecture: Multithreading, ONNX, and WebGPU Memory Management]]> https://virtualsach.in/blog/2026-07-browser-side-agentic-engine-architecture https://virtualsach.in/blog/2026-07-browser-side-agentic-engine-architecture Mon, 20 Jul 2026 05:30:00 GMT <![CDATA[Building a 100% Offline Voice-Controlled Browser Agent with FunctionGemma and WebGPU]]> https://virtualsach.in/blog/2026-07-offline-voice-agent-functiongemma-webgpu https://virtualsach.in/blog/2026-07-offline-voice-agent-functiongemma-webgpu Mon, 20 Jul 2026 04:30:00 GMT <![CDATA[When BGP Local-Pref Steered Us into a Routing Loop]]> https://virtualsach.in/blog/2026-07-bgp-local-pref-routing-loop https://virtualsach.in/blog/2026-07-bgp-local-pref-routing-loop Sun, 19 Jul 2026 16:35:00 GMT <![CDATA[I Learned BGP on a Delhi Rooftop, Not in a Lab]]> https://virtualsach.in/blog/spectranet-bgp-rooftop-wimax-fieldengineering https://virtualsach.in/blog/spectranet-bgp-rooftop-wimax-fieldengineering Sun, 19 Jul 2026 15:30:00 GMT <![CDATA[The Edge Intelligence Curve: 135M vs 500M Browser LLMs]]> https://virtualsach.in/blog/2026-07-debugging-webgpu-llm-intelligence-curves https://virtualsach.in/blog/2026-07-debugging-webgpu-llm-intelligence-curves Sun, 19 Jul 2026 09:00:00 GMT <![CDATA[Everyone Told Me Client-Side LLMs Were a Gimmick. They Were Wrong.]]> https://virtualsach.in/blog/2026-07-zero-latency-client-side-agentic-ai https://virtualsach.in/blog/2026-07-zero-latency-client-side-agentic-ai Sun, 19 Jul 2026 04:30:00 GMT <![CDATA[The App-ID Lie: Why We Ripped Out Cisco Firepower and What We Learned]]> https://virtualsach.in/blog/2026-07-app-id-vs-firepower-ngfw https://virtualsach.in/blog/2026-07-app-id-vs-firepower-ngfw Sun, 19 Jul 2026 00:00:00 GMT <![CDATA[GENEVE vs VXLAN: Why We Re-Engineered 400 Hypervisors During an Live Cloud Migration]]> https://virtualsach.in/blog/2026-07-nsxt-geneve-vs-vxlan-overlay-migration https://virtualsach.in/blog/2026-07-nsxt-geneve-vs-vxlan-overlay-migration Sun, 19 Jul 2026 00:00:00 GMT <![CDATA[We Built a Tier-3 Data Center From Scratch. Here Is What Nobody Tells You.]]> https://virtualsach.in/blog/2026-07-tier3-dc-build-from-scratch https://virtualsach.in/blog/2026-07-tier3-dc-build-from-scratch Sun, 19 Jul 2026 00:00:00 GMT <![CDATA[The Azure ExpressRoute BGP Steering Incident: 3 Weeks of Asymmetric Drops]]> https://virtualsach.in/blog/2026-07-azure-expressroute-bgp-steering-incident https://virtualsach.in/blog/2026-07-azure-expressroute-bgp-steering-incident Sat, 18 Jul 2026 00:00:00 GMT <![CDATA[How I Migrated 500 Enterprise VMs Live Without Changing a Single IP Address]]> https://virtualsach.in/blog/2026-07-live-migration-500-vms-zero-ip-change https://virtualsach.in/blog/2026-07-live-migration-500-vms-zero-ip-change Sat, 18 Jul 2026 00:00:00 GMT <![CDATA[Shipping Four Production Products as a Solo Architect using AI Agent Systems]]> https://virtualsach.in/blog/2026-07-shipped-four-products-solo-ai-team https://virtualsach.in/blog/2026-07-shipped-four-products-solo-ai-team Wed, 01 Jul 2026 00:00:00 GMT <![CDATA[Zero-Trust Polyglot Firewall Management: Unifying Palo Alto, Checkpoint & Cisco Rules]]> https://virtualsach.in/blog/2026-07-zero-trust-firewall-polyglot-browser https://virtualsach.in/blog/2026-07-zero-trust-firewall-polyglot-browser Wed, 01 Jul 2026 00:00:00 GMT <![CDATA[Model Context Protocol (MCP): The Universal API Gateway for Agentic Systems]]> https://virtualsach.in/blog/2026-06-mcp-the-universal-api-gateway-for-agents https://virtualsach.in/blog/2026-06-mcp-the-universal-api-gateway-for-agents Mon, 01 Jun 2026 00:00:00 GMT <![CDATA[Capability Attenuation: Scoped Tokens & Firewalls for AI Subagents]]> https://virtualsach.in/blog/2026-05-capability-attenuation-subagent-guardrails https://virtualsach.in/blog/2026-05-capability-attenuation-subagent-guardrails Sun, 10 May 2026 03:30:00 GMT <![CDATA[Token Economics: Applying BGP AS-Path Prepending Principles to LLM Model Steering]]> https://virtualsach.in/blog/2026-03-token-economics-bgp-routing https://virtualsach.in/blog/2026-03-token-economics-bgp-routing Sun, 01 Mar 2026 00:00:00 GMT <![CDATA[Edge-Native LLM Circuit Breakers: Low-Latency Failover via Cloudflare Workers AI]]> https://virtualsach.in/blog/edge-llm-circuit-breaker https://virtualsach.in/blog/edge-llm-circuit-breaker Sun, 01 Feb 2026 00:00:00 GMT <![CDATA[Your AI Agent Has a Thermal Problem: Circuit Breakers for LLM Runtimes]]> https://virtualsach.in/blog/2026-01-circuit-breakers-for-agentic-systems https://virtualsach.in/blog/2026-01-circuit-breakers-for-agentic-systems Thu, 01 Jan 2026 00:00:00 GMT <![CDATA[Observability on a Budget: Optimizing Cloud Log Ingestion Costs]]> https://virtualsach.in/blog/observability-on-budget https://virtualsach.in/blog/observability-on-budget Thu, 10 Apr 2025 00:00:00 GMT <![CDATA[The Agentic System That Worked Perfectly — Until It Didn't]]> https://virtualsach.in/blog/2025-03-agentic-system-blast-radius-incident https://virtualsach.in/blog/2025-03-agentic-system-blast-radius-incident Mon, 10 Mar 2025 03:30:00 GMT <![CDATA[The Factory: Building Azure DevSecFinOps at Scale]]> https://virtualsach.in/blog/azure-devsecfinops-factory https://virtualsach.in/blog/azure-devsecfinops-factory Fri, 14 Feb 2025 00:00:00 GMT <![CDATA[Uncovering Hidden Tech Debt: Cloud Landing Zone Security Audits]]> https://virtualsach.in/blog/security-audit-tech-debt https://virtualsach.in/blog/security-audit-tech-debt Wed, 15 Jan 2025 00:00:00 GMT <![CDATA[The Pivot: Transitioning from Hands-On Engineer to Cloud Architect]]> https://virtualsach.in/blog/engineer-to-architect https://virtualsach.in/blog/engineer-to-architect Tue, 05 Nov 2024 00:00:00 GMT <![CDATA[FinOps PR Guardrails: Preventing $50,000 Cloud Cost Spikes Before terraform apply]]> https://virtualsach.in/blog/infracost-finops-pr-guardrails https://virtualsach.in/blog/infracost-finops-pr-guardrails Wed, 18 Sep 2024 03:30:00 GMT <![CDATA[Blameless Post-Mortems: Fixing Systems, Not People]]> https://virtualsach.in/blog/blameless-culture-post-mortem https://virtualsach.in/blog/blameless-culture-post-mortem Thu, 12 Sep 2024 00:00:00 GMT <![CDATA[Policy as Code: Blocking Non-Compliant Terraform PRs at the CI/CD Pipeline Gate]]> https://virtualsach.in/blog/checkov-iac-security-pipeline-gate https://virtualsach.in/blog/checkov-iac-security-pipeline-gate Mon, 22 Jul 2024 03:30:00 GMT <![CDATA[BGP as a FinOps Tool: Optimizing Cloud Data Egress Costs]]> https://virtualsach.in/blog/bgp-attributes-cost-saving https://virtualsach.in/blog/bgp-attributes-cost-saving Tue, 02 Jul 2024 00:00:00 GMT <![CDATA[The BGP Steering Incident That Killed Our Low-Latency Guarantee]]> https://virtualsach.in/blog/2024-06-expressroute-bgp-local-pref-incident https://virtualsach.in/blog/2024-06-expressroute-bgp-local-pref-incident Tue, 18 Jun 2024 03:30:00 GMT <![CDATA[Azure ExpressRoute & BGP: Multi-Region Hybrid Routing Architecture]]> https://virtualsach.in/blog/2024-05-hybrid-cloud-bridge https://virtualsach.in/blog/2024-05-hybrid-cloud-bridge Fri, 10 May 2024 03:30:00 GMT <![CDATA[Shift-Left Cloud Security: Blocking Rogue Ingress with Checkov & Terraform CI/CD]]> https://virtualsach.in/blog/2024-03-terraform-checkov-iac-security-factory https://virtualsach.in/blog/2024-03-terraform-checkov-iac-security-factory Tue, 19 Mar 2024 03:30:00 GMT <![CDATA[Azure DevSecFinOps: Automating Governance at Scale]]> https://virtualsach.in/blog/2024-02-azure-devsecfinops-factory https://virtualsach.in/blog/2024-02-azure-devsecfinops-factory Sun, 18 Feb 2024 03:30:00 GMT <![CDATA[The Pull Request That Blocked $47K/Month in Cloud Spend]]> https://virtualsach.in/blog/2024-02-checkov-infracost-47k-pr-gate https://virtualsach.in/blog/2024-02-checkov-infracost-47k-pr-gate Wed, 14 Feb 2024 03:30:00 GMT <![CDATA[Azure ExpressRoute BGP Route Weight Tuning & Active-Active WAN Steering]]> https://virtualsach.in/blog/azure-expressroute-bgp-steering https://virtualsach.in/blog/azure-expressroute-bgp-steering Thu, 01 Feb 2024 00:00:00 GMT <![CDATA[BGP Local-Pref Steering: Eliminating Asymmetric Routing Across Dual Azure ExpressRoute Circuits]]> https://virtualsach.in/blog/azure-expressroute-bgp-local-pref https://virtualsach.in/blog/azure-expressroute-bgp-local-pref Wed, 01 Nov 2023 00:00:00 GMT <![CDATA[Automating Cloud Hygiene: Reclaiming Unattached Managed Disks & Public IPs at Scale]]> https://virtualsach.in/blog/azure-unattached-disk-cleanup-automation https://virtualsach.in/blog/azure-unattached-disk-cleanup-automation Tue, 10 Oct 2023 03:30:00 GMT <![CDATA[Azure Enterprise Scale Landing Zone: Hub-and-Spoke BGP Steering & Checkov Gates]]> https://virtualsach.in/blog/2023-07-azure-landing-zone-hub-spoke-design https://virtualsach.in/blog/2023-07-azure-landing-zone-hub-spoke-design Sat, 01 Jul 2023 00:00:00 GMT <![CDATA[The Azure Management Group Hierarchy That Broke 14 Business Units at Once]]> https://virtualsach.in/blog/2023-03-azure-caf-management-group-hierarchy-incident https://virtualsach.in/blog/2023-03-azure-caf-management-group-hierarchy-incident Wed, 08 Mar 2023 03:30:00 GMT <![CDATA[Day-0 Firewall Rules: Automating Security Baseline Insertion]]> https://virtualsach.in/blog/day-0-firewall-rules https://virtualsach.in/blog/day-0-firewall-rules Mon, 05 Dec 2022 00:00:00 GMT <![CDATA[The Kubernetes CNI Bug That Isolated 140 Production Pods at Midnight]]> https://virtualsach.in/blog/2022-11-kubernetes-ncp-cni-networkpolicy-translation https://virtualsach.in/blog/2022-11-kubernetes-ncp-cni-networkpolicy-translation Mon, 14 Nov 2022 03:30:00 GMT <![CDATA[The Zero Trust Lie: Why Default-Deny DFW Microsegmentation Requires Planning]]> https://virtualsach.in/blog/zero-trust-lie-dfw https://virtualsach.in/blog/zero-trust-lie-dfw Wed, 12 Oct 2022 00:00:00 GMT <![CDATA[Automating Security: Syncing Policy Matrices with PowerNSX]]> https://virtualsach.in/blog/automating-security-powernsx https://virtualsach.in/blog/automating-security-powernsx Thu, 18 Aug 2022 00:00:00 GMT <![CDATA[Recovering from a 400-Resource Terraform State Drift Emergency]]> https://virtualsach.in/blog/2022-05-terraform-state-lock-drift-reconciliation https://virtualsach.in/blog/2022-05-terraform-state-lock-drift-reconciliation Fri, 27 May 2022 03:30:00 GMT <![CDATA[Terraform State Disasters: Recovering Corrupted Remote State Locks]]> https://virtualsach.in/blog/terraform-state-disaster https://virtualsach.in/blog/terraform-state-disaster Tue, 10 May 2022 00:00:00 GMT <![CDATA[Translating Kubernetes NetworkPolicies to NSX-T Distributed Firewall Rules]]> https://virtualsach.in/blog/kubernetes-ncp-cni-networkpolicy-translation https://virtualsach.in/blog/kubernetes-ncp-cni-networkpolicy-translation Tue, 12 Apr 2022 03:30:00 GMT <![CDATA[When Kubernetes Met NSX-T: Container Networking with NCP CNI]]> https://virtualsach.in/blog/kubernetes-met-nsxt https://virtualsach.in/blog/kubernetes-met-nsxt Mon, 14 Feb 2022 00:00:00 GMT <![CDATA[The Ansible Tower Pipeline That Wiped the Wrong Environment]]> https://virtualsach.in/blog/2021-11-ansible-tower-ztp-wrong-environment-incident https://virtualsach.in/blog/2021-11-ansible-tower-ztp-wrong-environment-incident Mon, 22 Nov 2021 03:30:00 GMT <![CDATA[Declarative Networking: Automating NSX-T Fabric with Ansible]]> https://virtualsach.in/blog/defining-network-ansible-nsxt https://virtualsach.in/blog/defining-network-ansible-nsxt Sat, 20 Nov 2021 00:00:00 GMT <![CDATA[Zero-Touch Pod Decommissioning: Automated Teardown via Ansible & NSX-T API]]> https://virtualsach.in/blog/zero-touch-pod-teardown-undeploy https://virtualsach.in/blog/zero-touch-pod-teardown-undeploy Fri, 01 Oct 2021 00:00:00 GMT <![CDATA[Zero-Touch Datacenter Provisioning: Ansible Tower Meets NSX-T Policy API]]> https://virtualsach.in/blog/2021-09-ansible-tower-zero-touch-nsxt-datacenter https://virtualsach.in/blog/2021-09-ansible-tower-zero-touch-nsxt-datacenter Tue, 14 Sep 2021 03:30:00 GMT <![CDATA[DNS & Reverse PTR Integrity: Why Missing PTR Records Break NSX-T Manager Federation]]> https://virtualsach.in/blog/dns-ptr-integrity-nsxt-federation https://virtualsach.in/blog/dns-ptr-integrity-nsxt-federation Tue, 14 Sep 2021 03:30:00 GMT <![CDATA[From CLI to Code: Standardizing Network Infrastructure Pipelines]]> https://virtualsach.in/blog/2023-12-from-cli-to-code https://virtualsach.in/blog/2023-12-from-cli-to-code Sun, 15 Aug 2021 03:30:00 GMT <![CDATA[One-Click Nested SDDC Deployment: Automated vSphere & NSX-T Labs via Ansible]]> https://virtualsach.in/blog/2021-06-one-click-nested-sddc-ansible https://virtualsach.in/blog/2021-06-one-click-nested-sddc-ansible Tue, 01 Jun 2021 00:00:00 GMT <![CDATA[Ansible Galaxy Role Optimization: Structuring Modular Playbooks for SDDC Code]]> https://virtualsach.in/blog/ansible-galaxy-modular-sddc-playbooks https://virtualsach.in/blog/ansible-galaxy-modular-sddc-playbooks Mon, 05 Apr 2021 03:30:00 GMT <![CDATA[Transit VLAN Isolation: Why Dual-Homed Transit Segments Prevent Route Leaks]]> https://virtualsach.in/blog/transit-vlan-isolation-bgp-leaks https://virtualsach.in/blog/transit-vlan-isolation-bgp-leaks Thu, 18 Feb 2021 03:30:00 GMT <![CDATA[The Great Migration: Moving Production from NSX-V to NSX-T]]> https://virtualsach.in/blog/nsx-v-to-t-migration https://virtualsach.in/blog/nsx-v-to-t-migration Wed, 20 Jan 2021 00:00:00 GMT <![CDATA[vRA 8.2 Blueprint Engineering: Automating Multi-Node Tenant Pod Provisioning]]> https://virtualsach.in/blog/vra-8-blueprint-automation-engineering https://virtualsach.in/blog/vra-8-blueprint-automation-engineering Fri, 15 Jan 2021 03:30:00 GMT <![CDATA[Resource Contention: Balancing 320GB RAM & 20 Cores Across Concurrent Nested Pods]]> https://virtualsach.in/blog/resource-contention-sddc-pod-balancing https://virtualsach.in/blog/resource-contention-sddc-pod-balancing Mon, 30 Nov 2020 03:30:00 GMT <![CDATA[The ovftool Silent Failure: Automating OVF Deployments at Scale Without Headless Timeout Crashes]]> https://virtualsach.in/blog/ovftool-silent-failure-answerfile https://virtualsach.in/blog/ovftool-silent-failure-answerfile Mon, 10 Aug 2020 03:30:00 GMT <![CDATA[Bridging Physical and Virtual: Arista Hardware VTEP Integration]]> https://virtualsach.in/blog/bridging-physical-virtual-arista-hw-vtep https://virtualsach.in/blog/bridging-physical-virtual-arista-hw-vtep Mon, 18 May 2020 00:00:00 GMT <![CDATA[The Transitive Routing Trap: Avoiding Loop Disasters in Overlay Networks]]> https://virtualsach.in/blog/the-transitive-routing-trap https://virtualsach.in/blog/the-transitive-routing-trap Thu, 05 Mar 2020 00:00:00 GMT <![CDATA[NSX-V to NSX-T Surgery: In-Place Migration Blueprints]]> https://virtualsach.in/blog/2023-08-nsx-v-to-t-surgery https://virtualsach.in/blog/2023-08-nsx-v-to-t-surgery Sat, 15 Feb 2020 03:30:00 GMT <![CDATA[Stretching VLANs Safely: L2VPN Architecture with NSX Edge]]> https://virtualsach.in/blog/stretching-vlans-l2vpn https://virtualsach.in/blog/stretching-vlans-l2vpn Fri, 10 Jan 2020 00:00:00 GMT <![CDATA[Zero-Trust Micro-Segmentation: vRealize Network Insight (vRNI) Flow Telemetry]]> https://virtualsach.in/blog/2020-01-vrni-flow-telemetry-microseg-planning https://virtualsach.in/blog/2020-01-vrni-flow-telemetry-microseg-planning Wed, 01 Jan 2020 00:00:00 GMT <![CDATA[Data Center Log Forensics: Centralized Syslog with vRealize Log Insight]]> https://virtualsach.in/blog/csi-data-center-log-insight https://virtualsach.in/blog/csi-data-center-log-insight Thu, 05 Dec 2019 00:00:00 GMT <![CDATA[Changing Engines in Mid-Flight: Live Upgrade from NSX-V to NSX-T]]> https://virtualsach.in/blog/2021-03-changing-engines-nsxt https://virtualsach.in/blog/2021-03-changing-engines-nsxt Sun, 10 Nov 2019 03:30:00 GMT <![CDATA[BGP vs OSPF: Choosing Dynamic Routing Protocols for Multi-Tenant Overlay Gateways]]> https://virtualsach.in/blog/bgp-vs-ospf-nested-overlay-gateways https://virtualsach.in/blog/bgp-vs-ospf-nested-overlay-gateways Tue, 05 Nov 2019 03:30:00 GMT <![CDATA[Debugging Flow Telemetry: Using vRealize Network Insight (vRNI)]]> https://virtualsach.in/blog/debugging-flows-vrni https://virtualsach.in/blog/debugging-flows-vrni Sun, 25 Aug 2019 00:00:00 GMT <![CDATA[Sub-Second BFD Failover: Configuring 50ms BFD Keepalives Between Physical Switches and Virtual Edges]]> https://virtualsach.in/blog/sub-second-bfd-failover-edge-nodes https://virtualsach.in/blog/sub-second-bfd-failover-edge-nodes Tue, 20 Aug 2019 03:30:00 GMT <![CDATA[Direct Link Hybrid Bridging: Connecting Bare-Metal Oracle RAC to SoftLayer SDDCs]]> https://virtualsach.in/blog/ibm-softlayer-direct-link-baremetal https://virtualsach.in/blog/ibm-softlayer-direct-link-baremetal Tue, 18 Jun 2019 03:30:00 GMT <![CDATA[Protocol Wars: Why GENEVE Defeated VXLAN for Overlay Networks]]> https://virtualsach.in/blog/protocol-wars-vxlan-vs-geneve https://virtualsach.in/blog/protocol-wars-vxlan-vs-geneve Fri, 12 Apr 2019 00:00:00 GMT <![CDATA[Bridging Physical Bare-Metal to VMware NSX Overlays with Arista HW-VTEP & OVSDB]]> https://virtualsach.in/blog/2019-03-arista-hw-vtep-ovsdb-nsx-geneve https://virtualsach.in/blog/2019-03-arista-hw-vtep-ovsdb-nsx-geneve Fri, 01 Mar 2019 00:00:00 GMT <![CDATA[The MTU 9000 Trap: Debugging Geneve Overlay Encapsulation Packet Drops]]> https://virtualsach.in/blog/mtu-9000-trap-geneve-drops https://virtualsach.in/blog/mtu-9000-trap-geneve-drops Sat, 01 Dec 2018 00:00:00 GMT <![CDATA[Debugging Phantom Flows: Using vRNI Latency Telemetry for SDN Microsegmentation]]> https://virtualsach.in/blog/vrni-flow-telemetry-microsegmentation https://virtualsach.in/blog/vrni-flow-telemetry-microsegmentation Tue, 20 Nov 2018 03:30:00 GMT <![CDATA[The Magic of HCX: Bulk Live vMotion Across Hybrid Clouds]]> https://virtualsach.in/blog/magic-of-hcx-migration https://virtualsach.in/blog/magic-of-hcx-migration Tue, 20 Nov 2018 00:00:00 GMT <![CDATA[Nested ESXi Virtualization: Exposing Hardware-Assisted VT-x/EPT to Hypervisors]]> https://virtualsach.in/blog/nested-esxi-hardware-assisted-vt-x https://virtualsach.in/blog/nested-esxi-hardware-assisted-vt-x Fri, 22 Jun 2018 03:30:00 GMT <![CDATA[Zero IP Re-Numbering: VMware HCX Bulk Live Migration of 200+ Enterprise VMs]]> https://virtualsach.in/blog/2018-05-hcx-bulk-live-migration-zero-ip-change https://virtualsach.in/blog/2018-05-hcx-bulk-live-migration-zero-ip-change Tue, 01 May 2018 00:00:00 GMT <![CDATA[CSI Data Center: Using vRealize Log Insight for Root-Cause Packet Trace Parsing]]> https://virtualsach.in/blog/vrealize-log-insight-sddc-troubleshooting https://virtualsach.in/blog/vrealize-log-insight-sddc-troubleshooting Sat, 14 Oct 2017 03:30:00 GMT <![CDATA[VPN Scaling Under Load: Tuning Cisco AnyConnect Remote Access]]> https://virtualsach.in/blog/vpn-nightmare-anyconnect https://virtualsach.in/blog/vpn-nightmare-anyconnect Sat, 12 Aug 2017 00:00:00 GMT <![CDATA[Tuning Cisco Firepower: Fixing Snort Engine Packet Drops]]> https://virtualsach.in/blog/tuning-cisco-firepower https://virtualsach.in/blog/tuning-cisco-firepower Mon, 10 Apr 2017 00:00:00 GMT <![CDATA[Automating Multi-Vendor Firewall Audits with Python Netmiko & Paramiko]]> https://virtualsach.in/blog/2017-02-netmiko-python-firewall-mass-audit https://virtualsach.in/blog/2017-02-netmiko-python-firewall-mass-audit Wed, 01 Feb 2017 00:00:00 GMT <![CDATA[SD-WAN Evolution: Migrating Legacy MPLS Sites to Cisco Viptela & Velacloud Overlay]]> https://virtualsach.in/blog/cisco-viptela-sdwan-migration https://virtualsach.in/blog/cisco-viptela-sdwan-migration Fri, 20 Jan 2017 03:30:00 GMT <![CDATA[The Pivot: Transitioning from Manual CLI Engineer to Python Automation]]> https://virtualsach.in/blog/the-pivot-cli-to-python https://virtualsach.in/blog/the-pivot-cli-to-python Fri, 20 Jan 2017 00:00:00 GMT <![CDATA[The SSL Blind Spot: Implementing Outbound Inspection without Breaking Privacy]]> https://virtualsach.in/blog/ssl-decryption-blind-spot https://virtualsach.in/blog/ssl-decryption-blind-spot Sat, 15 Oct 2016 00:00:00 GMT <![CDATA[AnyConnect Acceleration: Why DTLS Over UDP Prevents TCP Meltdown on VPN Gateways]]> https://virtualsach.in/blog/cisco-anyconnect-dtls-udp-acceleration https://virtualsach.in/blog/cisco-anyconnect-dtls-udp-acceleration Mon, 12 Sep 2016 03:30:00 GMT <![CDATA[SSL Certificate Hell: Preventing Unplanned Outages at Scale]]> https://virtualsach.in/blog/ssl-certificate-hell https://virtualsach.in/blog/ssl-certificate-hell Mon, 20 Jun 2016 00:00:00 GMT <![CDATA[Legacy Load Balancer Migration: Cisco ACE 4710 to F5 BIG-IP LTM iRules]]> https://virtualsach.in/blog/2016-04-cisco-ace-to-f5-ltm-irules-migration https://virtualsach.in/blog/2016-04-cisco-ace-to-f5-ltm-irules-migration Fri, 01 Apr 2016 00:00:00 GMT <![CDATA[Tuning Next-Gen IPS: Balancing Snort VRT Rules and Zero-False-Positive SLAs]]> https://virtualsach.in/blog/cisco-ngips-snort-signature-tuning https://virtualsach.in/blog/cisco-ngips-snort-signature-tuning Sun, 14 Feb 2016 03:30:00 GMT <![CDATA[The Firewall Polyglot: Translating Semantics Across Vendor Estates]]> https://virtualsach.in/blog/firewall-polyglot https://virtualsach.in/blog/firewall-polyglot Sun, 14 Feb 2016 00:00:00 GMT <![CDATA[Checkpoint SmartConsole R77: Cleaning 2,000 Legacy Rules Without Causing Outages]]> https://virtualsach.in/blog/checkpoint-smartconsole-r77-policy-cleanup https://virtualsach.in/blog/checkpoint-smartconsole-r77-policy-cleanup Sun, 08 Nov 2015 03:30:00 GMT <![CDATA[Firewall Hell: Auditing & Cleaning 10,000+ Legacy Rule Sets]]> https://virtualsach.in/blog/firewall-hell-managing-policies https://virtualsach.in/blog/firewall-hell-managing-policies Sat, 05 Sep 2015 00:00:00 GMT <![CDATA[Identity & Proxy Overhaul: Migrating 10,000 Users from Cisco ACS to ISE & McAfee Gateway]]> https://virtualsach.in/blog/cisco-acs-to-ise-mcafee-proxy-migration https://virtualsach.in/blog/cisco-acs-to-ise-mcafee-proxy-migration Fri, 14 Aug 2015 03:30:00 GMT <![CDATA[Debugging Intermittent IPSec Phase 2 Re-Keying Drops Across Security Gateways]]> https://virtualsach.in/blog/checkpoint-ipsec-phase2-rekeying https://virtualsach.in/blog/checkpoint-ipsec-phase2-rekeying Thu, 14 May 2015 03:30:00 GMT <![CDATA[Hardware vs Software: F5 LTM to Software-Defined Load Balancing]]> https://virtualsach.in/blog/f5-vs-nsx-edge-migration https://virtualsach.in/blog/f5-vs-nsx-edge-migration Sat, 18 Apr 2015 00:00:00 GMT <![CDATA[The Death of Cisco ACE: Migrating Legacy Load Balancers to F5 BIG-IP]]> https://virtualsach.in/blog/death-of-cisco-ace https://virtualsach.in/blog/death-of-cisco-ace Sun, 12 Oct 2014 00:00:00 GMT <![CDATA[Tuning Cisco ACE & CSS Load Balancer HTTP Health Probes to Prevent False Failovers]]> https://virtualsach.in/blog/uri-http-probe-tuning-cisco-css-ace https://virtualsach.in/blog/uri-http-probe-tuning-cisco-css-ace Mon, 01 Sep 2014 00:00:00 GMT <![CDATA[Connecting Legacy IPv4 Services to Pure IPv6 Clients with NAT64 & DNS64]]> https://virtualsach.in/blog/nat64-legacy-ipv6 https://virtualsach.in/blog/nat64-legacy-ipv6 Wed, 01 Jan 2014 00:00:00 GMT <![CDATA[Data Center IPAM: Eliminating IP Conflicts with RackTables & iTop IT Operational Portal]]> https://virtualsach.in/blog/racktables-itop-ipam-asset-tracking https://virtualsach.in/blog/racktables-itop-ipam-asset-tracking Wed, 20 Nov 2013 03:30:00 GMT <![CDATA[Observability on a Zero-Dollar Budget: Combining rsyslog, RANCID, CACTI, Observium, and iTop]]> https://virtualsach.in/blog/rsyslog-observium-itop-open-source-ops https://virtualsach.in/blog/rsyslog-observium-itop-open-source-ops Thu, 12 Sep 2013 03:30:00 GMT <![CDATA[SIP ALG Nightmares: Fixing One-Way Audio Drops on Enterprise DMZ Firewalls]]> https://virtualsach.in/blog/sip-alg-voip-firewall-pinholes https://virtualsach.in/blog/sip-alg-voip-firewall-pinholes Sat, 18 May 2013 03:30:00 GMT <![CDATA[Hot P2V Migrations: Re-building RHEL initrd & Kernel Modules for vSphere ESXi]]> https://virtualsach.in/blog/p2v-migration-linux-vmware https://virtualsach.in/blog/p2v-migration-linux-vmware Wed, 01 May 2013 00:00:00 GMT <![CDATA[IPv6 Transition Strategies: Dual-Stack Coexistence with A10 Networks ADC NAT-PT]]> https://virtualsach.in/blog/a10-adc-nat-pt-ipv6-coexistence https://virtualsach.in/blog/a10-adc-nat-pt-ipv6-coexistence Mon, 01 Apr 2013 00:00:00 GMT <![CDATA[The Death of Spanning Tree: Surviving a Multi-Switch L2 Broadcast Storm]]> https://virtualsach.in/blog/death-of-spanning-tree https://virtualsach.in/blog/death-of-spanning-tree Fri, 01 Mar 2013 00:00:00 GMT <![CDATA[Multi-Tenant Firewalls: Partitioning Cisco FWSM Security Contexts & Advanced MPF]]> https://virtualsach.in/blog/cisco-fwsm-nexus-7000-security-contexts https://virtualsach.in/blog/cisco-fwsm-nexus-7000-security-contexts Mon, 05 Nov 2012 03:30:00 GMT <![CDATA[Proactive Capacity Planning with Cacti Spine C-Poller & SNMP Telemetry]]> https://virtualsach.in/blog/capacity-planning-cacti https://virtualsach.in/blog/capacity-planning-cacti Mon, 01 Oct 2012 00:00:00 GMT <![CDATA[Nexus 7010 vPC Architecture: Eliminating Spanning-Tree Topology Flaps]]> https://virtualsach.in/blog/nexus-7010-vpc-spanning-tree-tuning https://virtualsach.in/blog/nexus-7010-vpc-spanning-tree-tuning Fri, 14 Sep 2012 03:30:00 GMT <![CDATA[Solving IPv4 Exhaustion: Building an MP-BGP Dual-Stack IPv6 Carrier Core]]> https://virtualsach.in/blog/ipv6-exhaustion-dual-stack https://virtualsach.in/blog/ipv6-exhaustion-dual-stack Wed, 01 Aug 2012 00:00:00 GMT <![CDATA[Early GSLB: Traffic Steering Across Datacenters with Cisco CSS & GSS]]> https://virtualsach.in/blog/cisco-css-gss-early-gslb-load-balancing https://virtualsach.in/blog/cisco-css-gss-early-gslb-load-balancing Tue, 10 Apr 2012 03:30:00 GMT <![CDATA[Scaling BGP Core: Deploying Route Reflectors & AS-Path Prepending Across ISP Transit]]> https://virtualsach.in/blog/bgp-route-reflectors-as-path-prepending https://virtualsach.in/blog/bgp-route-reflectors-as-path-prepending Wed, 15 Feb 2012 03:30:00 GMT <![CDATA[The Route Redistribution Loop that Took Down the Core]]> https://virtualsach.in/blog/route-redistribution-loop-outage https://virtualsach.in/blog/route-redistribution-loop-outage Thu, 15 Dec 2011 03:30:00 GMT <![CDATA[High Availability Core: Tuning Cisco 7606 & 7206 HSRP Virtual Gateway Failover]]> https://virtualsach.in/blog/cisco-7606-7206-hsrp-gateway-failover https://virtualsach.in/blog/cisco-7606-7206-hsrp-gateway-failover Sat, 20 Aug 2011 03:30:00 GMT <![CDATA[Building Two Tier-3 Data Centers from Scratch: PAC Units, Dual Feeders & Fiber Links]]> https://virtualsach.in/blog/building-data-center-from-scratch https://virtualsach.in/blog/building-data-center-from-scratch Wed, 01 Jun 2011 00:00:00 GMT <![CDATA[RANCID & Subversion: How Automated Configuration Backups Saved a Core Router]]> https://virtualsach.in/blog/rancid-saved-the-network https://virtualsach.in/blog/rancid-saved-the-network Sat, 01 Jan 2011 00:00:00 GMT <![CDATA[Debugging RF Interference & Packet Loss on Rooftop WiMAX Tower Antenna Links]]> https://virtualsach.in/blog/debugging-packet-loss-wimax https://virtualsach.in/blog/debugging-packet-loss-wimax Sun, 01 Aug 2010 00:00:00 GMT <![CDATA[UTM Polyglot: Multi-Vendor Firewall Troubleshooting across Cisco PIX, Juniper SRX, Fortinet & SonicWALL]]> https://virtualsach.in/blog/juniper-srx-fortinet-sonicwall-utm-polyglot https://virtualsach.in/blog/juniper-srx-fortinet-sonicwall-utm-polyglot Sat, 22 May 2010 03:30:00 GMT <![CDATA[The Backhoe Rip: Surviving a Dual Fiber-Cut with Sub-Second BGP Failover]]> https://virtualsach.in/blog/fiber-cut-redundancy-lesson https://virtualsach.in/blog/fiber-cut-redundancy-lesson Sat, 01 May 2010 00:00:00 GMT <![CDATA[Telecom Edge Infrastructure: Ericsson RBS Base Station Quality & E1 TDM Trunking]]> https://virtualsach.in/blog/ericsson-telecom-rbs-bsc-quality https://virtualsach.in/blog/ericsson-telecom-rbs-bsc-quality Sun, 01 Nov 2009 00:00:00 GMT <![CDATA[Phantom Packet Loss: Debugging Half-Duplex Auto-Negotiation Mismatches]]> https://virtualsach.in/blog/phantom-packet-loss-duplex-mismatch https://virtualsach.in/blog/phantom-packet-loss-duplex-mismatch Sun, 01 Feb 2009 00:00:00 GMT <![CDATA[Artemis Hospital Infrastructure: Cisco ASA 5510 DMZ Segmentation & S2S IPSec VPN]]> https://virtualsach.in/blog/2009-01-cisco-asa-5510-dmz-ipsec-hospital https://virtualsach.in/blog/2009-01-cisco-asa-5510-dmz-ipsec-hospital Thu, 01 Jan 2009 00:00:00 GMT <![CDATA[Healthcare Telephony: Integrating Coral EPABX Voice Systems with Mission-Critical LANs]]> https://virtualsach.in/blog/coral-epabx-hospital-telephony https://virtualsach.in/blog/coral-epabx-hospital-telephony Mon, 10 Nov 2008 03:30:00 GMT <![CDATA[First Lines of Defense: Active Directory, WhatsUp Gold & MRTG Network Telemetry]]> https://virtualsach.in/blog/2008-11-active-directory-whatsup-gold-network-ops https://virtualsach.in/blog/2008-11-active-directory-whatsup-gold-network-ops Sat, 01 Nov 2008 00:00:00 GMT <![CDATA[Securing Hospital Airwaves: Deploying Cisco ACS 4.0 TACACS+ and Aironet Wireless at Artemis]]> https://virtualsach.in/blog/cisco-acs-4-tacacs-wireless-artemis https://virtualsach.in/blog/cisco-acs-4-tacacs-wireless-artemis Thu, 18 Sep 2008 03:30:00 GMT <![CDATA[Wireshark Packet Analysis: Diagnosing Spoofed TCP RST Attack Disruption]]> https://virtualsach.in/blog/wireshark-tcp-reset-attack-analysis https://virtualsach.in/blog/wireshark-tcp-reset-attack-analysis Tue, 01 Jul 2008 00:00:00 GMT