Sohaïb Rihane | Field NotesNotes on network architecture, automation, and security from Sohaïb Rihane, Senior Technical Consulting Engineer at Cisco.https://sohaibrihane.com/enThe Out-of-Band Paradoxhttps://sohaibrihane.com/blog/oob-management-paradox/https://sohaibrihane.com/blog/oob-management-paradox/Break-glass access must never depend on the infrastructure it is meant to rescue. What audits of console-server estates keep revealing, and the design rules for management paths that survive the bad day.Tue, 09 Jun 2026 00:00:00 GMTout-of-bandresilienceoperationsdesignRPKI: The Policy Was Perfect. The Validators Were Missing.https://sohaibrihane.com/blog/rpki-policy-without-validators/https://sohaibrihane.com/blog/rpki-policy-without-validators/A fleet-wide RPKI deployment that validated nothing on several transit edges, and the general lesson about verifying effect instead of configuration presence.Thu, 14 May 2026 00:00:00 GMTbgprpkirouting securityauditMost of Your Firewall Rules Have Never Matched a Packethttps://sohaibrihane.com/blog/firewall-rules-zero-hit/https://sohaibrihane.com/blog/firewall-rules-zero-hit/In audit after audit, the large majority of firewall rules turn out to have matched zero traffic. Here is how rule bases decay, why it matters, and a guardrail pattern for cleaning up without breaking production.Tue, 21 Apr 2026 00:00:00 GMTfirewallsecurityoperationscleanupYour MPLS Core Is Fine. Your VRF Import Policy Is the Problem.https://sohaibrihane.com/blog/vrf-route-leaking-east-west-blind-spot/https://sohaibrihane.com/blog/vrf-route-leaking-east-west-blind-spot/How VRF route leaking silently defeats a north-south firewall model, and why east-west traffic that resolves in the fabric never sees your security policy at all.Thu, 12 Mar 2026 00:00:00 GMTmplsvrfsecuritysegmentationTurning NetBox and Device Configs into a RAG Knowledge Basehttps://sohaibrihane.com/blog/netbox-rag-knowledge-base/https://sohaibrihane.com/blog/netbox-rag-knowledge-base/Why raw CSV exports fail in retrieval-augmented generation, how narrative chunking fixes them, and when to skip RAG entirely and give the model an API instead.Wed, 11 Feb 2026 00:00:00 GMTairagnetboxdocumentationReplacing the Corporate VPN with Cloudflare Zero Trusthttps://sohaibrihane.com/blog/cloudflare-warp-ztna-rollout/https://sohaibrihane.com/blog/cloudflare-warp-ztna-rollout/A company-wide ZTNA rollout with the Cloudflare One agent: identity-driven access profiles, device posture enforcement, and the end of the flat VPN subnet.Wed, 19 Nov 2025 00:00:00 GMTzero trustztnacloudflaresecurityMonitoring 200+ Network Devices with Zabbix, Graylog, and PagerDutyhttps://sohaibrihane.com/blog/monitoring-stack-zabbix-graylog/https://sohaibrihane.com/blog/monitoring-stack-zabbix-graylog/How I built a monitoring stack for a 200+ device fleet: SNMPv3 polling, centralized logging, meaningful triggers, and alerts that arrive with context instead of noise.Tue, 16 Sep 2025 00:00:00 GMTmonitoringzabbixgraylogobservabilityMigrating a Multi-Campus Network to Cisco Catalyst Centerhttps://sohaibrihane.com/blog/sda-catalyst-center-migration/https://sohaibrihane.com/blog/sda-catalyst-center-migration/Moving a multi-campus network of Catalyst 9300 and 9500 switches under Catalyst Center: template-driven configuration, streaming telemetry, and the assurance data that changed how the team troubleshoots.Tue, 10 Jun 2025 00:00:00 GMTciscocatalyst centerassurancecampus