Management address failover

In Devices → Add device / Edit settings → Connection, add internal, VPN or public static IPs and choose Primary. The existing host is Primary; fallbackHosts holds up to seven alternate IPv4/IPv6 addresses in priority order. All addresses must reach the same router, using its shared SSH/REST ports, credentials and jump-host configuration.

{
  "host": "10.10.10.1",
  "fallbackHosts": ["203.0.113.10", "2001:db8::10"],
  "port": 22,
  "username": "admin",
  "keyFilename": "/keys/home"
}

• A successful connection remembers its IP for 5 minutes, separately for each device and transport/port. New connections try that IP first; each successful connection renews the window. Failure clears the preference immediately. Without a cached success, Primary and then alternatives are tried in order, with a 30-second cooldown for failed addresses. Healthy pooled/Safe Mode sessions stay open even after expiry; commands already dispatched are never replayed on another IP.
• Device cards automatically refresh address observations every 4 seconds: open connections, remembered IP and remaining preference time, last failures, and untested addresses. These are real connection observations, not continuous probes of unused addresses. Primary is never rewritten; preference is in-memory and resets on server restart or device configuration replacement.
• SSH, SSH jump devices, SFTP, initial Safe Mode setup, REST probes and dashboard tests use this selection. Authentication/key errors stop that connection attempt; MAC-Telnet has no IP failover.
• Device cards and list_mikrotik_devices distinguish Connected, historical success, failed attempts and untested addresses. Test connection / Connect & Save reports the IP that authenticated.
• Failover happens before command dispatch. A lost command response is not automatically replayed on another IP or over SSH. An active Safe Mode transaction never migrates between connections.
• Existing single-address configurations remain valid. No router interface, routing or firewall settings are changed by adding management addresses to MCP.