01INSTALLATION
Choose the native package route.
Signed 51DDNS feed
51DDNS is not yet available from the official OpenWrt feeds. For a fresh native installation, use the signed 51DDNS feed for your OpenWrt release and architecture:
51ddns-agent — agent, init script and configurationluci-app-51ddns — web interface under Services → 51DDNS Remote Access
uclient-fetch -q -O /tmp/51ddns-repository.sh \
"https://www.51ddns.com/downloads/openwrt/install-repository.sh" && \
sh /tmp/51ddns-repository.sh
OpenWrt 24.10 uses opkg/IPK; 25.12 uses apk. Check the package feed and signature for your architecture before installing. If native packages are already installed, go straight to configuration below.
iStore and source builds
iStore lists packages for some targets, but its older 24.10 package may resolve to frpc 0.51.3, which cannot read the agent's TOML configuration. The agent needs frpc >= 0.52.0; the signed 51DDNS 24.10 feed provides a compatible dependency. Check the resolved version before enabling the service.
To build from source, use the OpenWrt SDK and the public package definitions. The agent is compiled from Go source by the OpenWrt build system.
make package/51ddns-agent/compile V=s
make package/luci-app-51ddns/compile V=s
Source and build notes →02CONFIGURATION
Connect the router in LuCI.
- 1
Choose the device record
The signed 51DDNS feed now provides luci-app-51ddns 0.1.5-r3 with 51ddns-agent 0.6.5-r4. For a pre-created device, copy its full ID from the console and use the Existing device ID (optional) field in LuCI. Keep that record and its seat. If you have not created a device, token-only registration can create one automatically, provided your account has a free device seat. Older LuCI versions without this field need a compatible native package upgrade; verify the OpenWrt release, architecture and saved identity before proceeding. Do not guess an ID, delete the device, reinstall, or use token-only activation for a pre-created record.
- 2
Open the LuCI page
Go to Services → 51DDNS Remote Access and inspect the saved device ID first. If it belongs to another record, stop and contact support; never replace it. Before a first binding, if the service is running without a saved identity, disable it and choose Save & Apply first. Enter this account's token and the exact existing device ID for a pre-created record, then enable, save and apply. Leave the ID empty only for token-only registration of a new device. Treat the token as a credential. Never run the website's one-click installer over native Agent/LuCI packages.
- 3
Verify the connection
The page shows the service state, agent version, current plan and expiry. A newly registered router also appears in the 51DDNS console.
/etc/init.d/51ddns-agent status
logread -e 51ddns-agent
03DATA & SECURITY
What leaves the router.
Sent to 51DDNS
Account/device credential, installation and device identifiers, platform and agent version, public IP, operational status and tunnel configuration metadata.
Not uploaded
The agent does not scan or upload arbitrary router files. Traffic visibility depends on the protocol selected by the user; prefer HTTPS and SSH.
Local storage
Credentials are stored below /etc/51ddns with restricted permissions. Runtime FRP configuration is temporary and recreated after reboot.
The operator of api.51ddns.com supplies the FRP configuration and therefore controls the relay endpoints used by the agent. Install only if you trust the service operator. Read the complete privacy notice.
04OPERATIONS
Troubleshoot or remove it.
Common checks
/etc/init.d/51ddns-agent status
logread -e 51ddns-agent
nslookup api.51ddns.com
HTTP 401 means the account token is invalid or revoked. Confirm system time, DNS and outbound HTTPS access before reporting a connection problem.
Disable and uninstall
/etc/init.d/51ddns-agent stop
/etc/init.d/51ddns-agent disable
opkg remove luci-app-51ddns 51ddns-agent
After removal, delete the router from the 51DDNS console if you no longer want it associated with your account.