When IPsec Suddenly Becomes One-Way Behind CGNAT We recently ran into an interesting IPsec issue across three branch sites. Each branch used the same basic design: FortiGate firewall at the branch Teltonika 5G router in front of the FortiGate NAT… Read moreWhen IPsec Suddenly Becomes One-Way Behind CGNAT
Overview During an IOS XE upgrade of a three-member Cisco Catalyst 9200L stack from 17.15.03 to 17.15.06, one stack member ended up in a boot loop and eventually dropped into ROMMON. The root cause was not a corrupted IOS XE… Read moreRecovering a Cisco Catalyst 9200L Stack After a Failed IOS XE Upgrade
Fortinet has changed the first-boot experience on newer FortiGate G-series appliances: before the firewall can be fully configured, it must be registered with FortiCare. On paper that sounds harmless. In the rack, with a fresh FortiGate-200G and no predefined WAN… Read moreFortiGate Forced FortiCare Registration: What Changed and How to Get a 200G Online
If you come from the Cisco world, Huawei WLAN HA can look a little unfamiliar at first. The good news: once you stop trying to force a “dedicated HA cable for everything” mindset onto it, the design gets a lot… Read moreHuawei AirEngine WLC HA with HSB: Keeping Active/Standby Simple
I ran into an issue on a Cisco 9800 WLC after upgrading to 17.12.6a with the standard install workflow. The installation itself completed successfully, but the controller did not boot cleanly on the first reload. What happened I started the… Read moreCisco 9800: Wrong Boot Variable After Upgrade to 17.12.6a
Purpose This note describes the multicast capability of Huawei SD-WAN, its functional principle, configuration concept, and constraints. The industry standard behind this feature is NGMVPN (Next Generation Multicast VPN) — Huawei refers to the SD-WAN implementation internally as “Multicast over… Read moreSD-WAN Multicast (NGMVPN)
Purpose This note describes the use of GRE tunnels in Huawei SD-WAN, their two primary use cases (connecting non-SD-WAN sites and IPv6 migration over IPv4 overlay), and the relevant constraints and configuration parameters. GRE in the SD-WAN Context GRE (Generic… Read moreSD-WAN GRE Tunnels and Layer 2 Connectivity
Purpose This note describes the conceptual structure of overlay/underlay, the available network topology models, VPN isolation, routing protocols, and CPE deployment modes in Huawei SD-WAN. Overlay vs. Underlay Underlay Network The underlay network is the physical network infrastructure on which… Read moreSD-WAN Topologies, Routing and Deployment Modes
Purpose This note explains the conceptual architecture of Huawei SD-WAN Solution, its layered structure, key components, acronyms, and typical deployment scenarios. Background and Motivation Enterprise WAN networks face four structural problems: Closed WAN architecture: Multi-cloud and multi-carrier connectivity is difficult… Read moreSD-WAN Solution – Overview, Architecture and Key Terms
Purpose This note summarizes the Huawei CPE device families used in the SD-WAN Solution, including their roles, characteristics, and typical use cases. CPE Roles in SD-WAN A CPE can take on different roles depending on configuration: Role Function Edge Gateway… Read moreSD-WAN CPE Devices – Huawei AR Series