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@jennifer/routeros

Cloud DDNS

File: src/topics/cloud.j. Path: /ip/cloud (CLOUD_PATH).

Background

Most home and small-office WANs get a dynamic public address - it changes, and everything that needs to reach the router from outside (road-warrior WireGuard, port forwards, Let's Encrypt) breaks with it. MikroTik's built-in answer is free and one flag away: the router registers <serial>.sn.mynetname.net with MikroTik's DDNS and keeps it pointed at the current address. Not a pretty name, but a stable one - and a CNAME in your own zone can dress it up.

Struct

jennifer
mt.CloudStatus { ddnsEnabled, dnsName, publicAddress, updateTime }

Functions

FunctionPurpose
enableCloudDns(c)register + force the first update
routerDnsName(c) → stringthe name, ready to dial (throws until assigned)
cloudStatus(c) → CloudStatusfull state incl. the seen public address
disableCloudDns(c)stop updating

Examples

The dynamic-IP VPN server recipe:

jennifer
mt.enableCloudDns($c);
def name as string init mt.routerDnsName($c);
io.printf("road warriors dial: %s:13231\n", $name);
mt.setupWireguardServer($c, "wgvpn", 13231, "10.100.0.1/24");
# the laptop's WireGuard config uses <name> as the endpoint

Detecting a WAN address change (host-side check):

jennifer
def st as mt.CloudStatus init mt.cloudStatus($c);
io.printf("public address per cloud: %s (updated %s)\n",
    $st.publicAddress, $st.updateTime);

Pitfalls

  • routerDnsName throws until the first update lands - after enableCloudDns, give it up to a minute (and the router needs working internet + DNS).
  • publicAddress is what MikroTik's servers saw - behind CGNAT it is not an address anyone can reach, and no DDNS fixes that (ask the ISP for a real address, or dial out with connectWireguard instead).
  • The updates talk to MikroTik's cloud - a privacy consideration on paranoid networks; the alternative is any third-party DDNS via scheduler + fetch scripts.
  • The name is per-device (serial-bound): replacing the hardware changes the name - a CNAME in your own zone insulates users.