JustASRV

Troubleshooting

Start with the hostname's Update history in the portal. Every request that reached JustASRV with a valid token is there, with the result, the caller's address and the client's User-Agent.

By symptom

Nothing in the update history

  • The device is not sending, or is not reaching https://ddns.justasrv.com. From the site, run curl -v https://ddns.justasrv.com/ip.
  • The device is sending over plain HTTP (see UniFi), or its certificate store is too old to trust Let's Encrypt.
  • The token is wrong. Rejected tokens do not appear on the host (a bad token cannot be tied to one), but SoMo sees them under Events › Auth failures.

badauth

The token is mistyped, revoked, or past its rotation grace period. Check which credential the device uses (the first characters are shown in the portal) and issue a new one if unsure.

nohost

The hostname in the request does not match the token's hostname (typo, or a token copied from a different site), or the host is disabled.

badip

The address to publish is not public. Most often the host accepts myip= and the device reports its private WAN address behind another router. Switch the host back to "use caller's address".

abuse / HTTP 429

The client is sending too often, or its address had repeated failed logins. Wait for the time in Retry-After, then fix the client's interval. A leftover device with an old token causes this for everyone behind the same public address: find and fix it.

Host shows STALE but the site is up

The device only reports changes. Set longer status thresholds on the host (see each router guide) or add a heartbeat updater.

DNS still shows the old address

  • Check what JustASRV published: the portal's Current address, and nslookup acme-main.ddns.justasrv.com 1.1.1.1.
  • Records have a 60-second TTL, but some resolvers and apps cache longer. VPN clients often cache the resolved address until the tunnel restarts.
  • If the portal shows "Waiting to publish", the DNS provider had an error; JustASRV retries automatically with backoff.

The address is the wrong one

JustASRV publishes the address the request came from. On dual-WAN sites the updater's traffic may leave through the other WAN: pin the updater's traffic to the right WAN, or give each WAN its own hostname.

Useful commands

curl -s https://ddns.justasrv.com/ip                               # what JustASRV sees you as
curl -si -u 'HOST:TOKEN' 'https://ddns.justasrv.com/nic/update?format=json'   # full response
nslookup acme-main.ddns.justasrv.com 1.1.1.1                      # what the world resolves