Routing and high availability
Routing decides where permitted traffic goes. Define the source networks, gateways, static routes, policy-routing needs, and return paths before changing a default gateway or advertising a route. Keep console or independent management access during routing work.
Use System → Routing for gateways, gateway groups, and static routes. Use gateway monitoring to distinguish a failed upstream from an unreachable monitoring target. Multi-WAN policy must account for NAT, state handling, DNS, VPN paths, and services that require a stable source address.
High availability adds configuration synchronization and failover behavior. Treat it as a complete design: peer addressing, state synchronization, virtual IP ownership, services, certificates, failure tests, and split-brain recovery. Test a controlled failover before relying on it.