Home › Dahua Help › DMSS not working or device offline: how to fix it
Applies to: Dahua NVRs, XVRs and IP cameras viewed through DMSS using P2P. Menu names vary between firmware versions.
Quick answer: If DMSS shows your device as offline, first check the recorder's P2P status. If it is not Online, make sure DHCP is on, set DNS to 8.8.8.8 and 8.8.4.4, check the network cable and reboot. If P2P is Online but the app still fails, delete and re-add the device in DMSS and update the app.
An offline device in DMSS is one of the most common Dahua support questions. The cause is almost always in one of three places: the recorder's network settings, the site's internet connection, or the app itself.
Working through them in that order saves time. The checks below need no special tools, and none of them affect your recordings.
Before you start
A monitor and mouse connected to the recorder, or access to its web interface on the local network
The device admin password
Access to the router, in case it needs restarting
Step 1: Check P2P status on the recorder
Open the network settings on the recorder and select P2P.
Confirm Enable is ticked.
Look at the status. If it reads Online, skip to Step 4. If it reads Offline, carry on with Step 2.
Step 2: Fix the recorder's network settings
Most offline cases come from an IP address or DNS problem. Open the TCP/IP settings (often Network > TCP/IP).
Switch DHCP on so the router hands the recorder a valid address, gateway and DNS.
Set Preferred DNS to 8.8.8.8 and Alternate DNS to 8.8.4.4. Some router-supplied DNS servers do not resolve Dahua's P2P servers reliably.
Apply the settings.
If your firmware has a network test tool (sometimes under Info > Network > Test), ping 8.8.8.8 and then google.com. A failed ping to 8.8.8.8 points to a cable or router problem; a failed ping to google.com alone points to DNS.
If you prefer a fixed IP address, set DHCP off only after noting the address, subnet mask and gateway the router gave you, and keep the DNS values above.
Step 3: Check cables and restart
Check the network cable between recorder and router. Try a different cable and router port.
Check the lights on the recorder's network port.
Restart the router, wait for it to come back, then reboot the recorder.
Check the P2P status again after a few minutes.
Step 4: Fix the app side
If the recorder shows Online but DMSS does not, the problem is on the phone.
Update DMSS from the app store.
Check the serial number saved in DMSS matches the one on the recorder.
Check the password saved in the app. If the device password was changed, edit it in the device settings in DMSS.
Delete the device from DMSS and add it again using the QR code.
Try the app on Wi-Fi and on mobile data to rule out a network block on one of them.
Troubleshooting
Problem
Likely cause
What to try
P2P offline, ping to 8.8.8.8 fails
No route to the internet
Check cable, router port and gateway address
P2P offline, ping to 8.8.8.8 works
DNS not resolving
Set DNS to 8.8.8.8 and 8.8.4.4
Offline after a router change
Recorder still using the old network range
Switch DHCP on, or set an address in the new range
Online on Wi-Fi but not mobile data
Mobile network or phone setting
Check DMSS is allowed to use mobile data
Was working, now offline everywhere
Firmware or app bug, or power cut
Reboot, update DMSS, and check for newer firmware
Some cameras black, others fine
Camera issue rather than P2P
Check the camera's status on the recorder
Frequently asked questions
Why does DMSS say my device is offline?
Usually the recorder cannot reach Dahua's P2P servers. Check P2P is enabled, DHCP and DNS are set correctly, and the network cable is connected.
Which DNS servers should I use for Dahua P2P?
Many people use 8.8.8.8 and 8.8.4.4. Other public DNS servers can work, but these are a common first step when P2P will not connect.
Will rebooting the recorder delete my footage?
No. A reboot restarts the recorder. Recordings and settings are kept.
DMSS works at home but not away. Why?
At home the app may be connecting over the local network. Away from home it relies on P2P, so check the recorder's P2P status reads Online.
Does a firmware update fix P2P problems?
Sometimes. If the network settings are correct and P2P still fails, a newer firmware version can help. Follow our firmware guide and update carefully.
Can Zenith Security Co. look at it remotely?
We are a supplier, not an installer, but we offer technical support by phone and bookable remote setup sessions.
Still showing offline? Call our technical line or book a remote setup session. Since 2012 we have supplied CCTV equipment from Wolverhampton to homeowners, businesses and installers, with delivery across England, Scotland and Wales. Installers can apply for a trade account for trade pricing.
