// CCTV & BROADBAND
CCTV not working after changing broadband? Here's what actually broke
You switched broadband provider, the new router went in, and now your camera app says the system is offline — even though the cameras clearly have power. This is one of the most common calls we get after a broadband change, and it's almost never the cameras' fault. Here's why a new router silently breaks CCTV, how the fix differs for cloud and older port-forwarded systems, and the one thing we'd urge you not to do. Rated 4.9 on Google.
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/01 — THE SYMPTOM
Everything worked until the new router arrived
The story is nearly always the same: the broadband switch went smoothly, the internet itself is fine, but the CCTV app now shows "offline", "connection failed" or an endlessly spinning wheel. The recorder may still show live pictures on its own monitor — proof the cameras are healthy — yet the moment you leave the house, nothing.
Nothing is broken. Your camera system was quietly configured around your old router, and the new one knows none of it. Four things cause almost every case of this:
- Port-forwarding rules that lived inside the old router and went back in the box with it.
- A recorder with a fixed IP address that no longer matches the new router's network range.
- UPnP — the automatic version of port forwarding — switched off on the new hub.
- Double NAT, if a mesh WiFi system is now sitting behind the provider's hub.
Which of these applies, and what the right fix is, depends on whether yours is a modern cloud/P2P system or an older port-forwarded DVR — they fail for different reasons and need different repairs. We'll take them in turn, including the honest security question most guides skip.
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/02 — WHAT BROKE
The settings that died with your old router
Port forwarding is the classic culprit. Older CCTV installs work by opening a "door" in the router that lets your phone reach the DVR or NVR from outside. Those rules live inside the router itself, so when the old one was unplugged, the rules went with it. The new router arrives with no doors open at all — and remote viewing dies instantly.
The second, sneakier problem is the recorder's own address. Installers often give a DVR a fixed (static) IP so the forwarding rule always points at the right box. If it was set to something like 192.168.1.100 but your new provider's hub uses a different range, the recorder is now stranded on a network that no longer exists — it can't even reach the internet, let alone your phone. Address ranges vary between providers, which is exactly why a swap that "should just work" often doesn't.
Finally, some systems relied on UPnP to open ports automatically. Plenty of current hubs ship with it disabled — and, in fairness, for sound security reasons, which we'll come back to below. The result is the same either way: the path from your phone to your recorder no longer exists. One more modern wrinkle: some newer providers — most 4G and 5G home broadband, Starlink’s standard plan, and a number of full-fibre networks — put you behind carrier-grade NAT, where you share a public address with other customers. Behind CGNAT, port forwarding simply cannot work no matter what you set, and the honest fixes are the camera maker’s cloud/P2P service, a VPN, or asking the provider whether a public IP is available.
/03 — TWO KINDS OF SYSTEM
Cloud (P2P) cameras and old-school DVRs need different fixes
Modern systems — Ring, Eufy, Tapo, and most recent Hikvision or Dahua kits used through the maker's own app — are "P2P" or cloud-connected. The recorder or camera phones home to the vendor's servers and your app meets it there, so no port forwarding is needed. After a broadband change these usually fail for one simple reason: the kit can't get online. Wired recorders may need their network settings moved onto the new range; WiFi cameras need the new network's name and password. A tip worth knowing before your next switch: if you set the new router's WiFi name and password to match the old ones, most wireless cameras reconnect on their own.
Older port-forwarded DVR systems — often reached via an IP address or DDNS name typed into the app — are a different job. Getting them going again means giving the recorder a valid address on the new network, then deciding how to make it reachable from outside, which is where the security question below really matters.
If your cameras sit in an outbuilding, there's an extra wrinkle — the link back to the house has to survive the router change too. Our guide to connecting garage CCTV to the house covers that side.
/04 — THE HIDDEN CULPRIT
Mesh WiFi and double NAT
A broadband change is often the moment people add mesh WiFi — and mesh is behind a surprising share of these callouts. If the mesh system is plugged into the provider's hub and both are acting as routers, you now have two networks stacked on top of each other: "double NAT". A port-forwarding rule on one router doesn't carry through the other, so remote viewing fails even if you configure one of them perfectly. Some cloud systems cope with double NAT; others become flaky or drop off entirely.
The clean fix is to have only one device doing the routing — usually by putting the provider's hub into modem or bridge mode so the mesh takes over. The setting's name and availability vary by provider, and some hubs don't offer it at all, in which case workarounds like an IP passthrough or DMZ setting pointed at the mesh can do the job — but they need doing carefully, or you trade one problem for another.
This is bread-and-butter work for us on business WiFi installations, where cameras, tills and door systems all have to survive a network change together — and exactly the same thinking applies to a home setup.
/05 — OUR HONEST ADVICE
When we'd tell you not to rebuild the old setup
Here's the part many guides skip: if your old router had port-forwarding rules pointing at a DVR, we'd think twice before recreating them. A forwarded port puts the recorder directly on the public internet, where automated scanners find it within hours. That was normal practice a decade ago; today, older DVRs that no longer receive firmware updates are among the most commonly hijacked devices in a home. If your recorder is ancient and unsupported, the honest answer may be that it shouldn't be internet-facing at all.
What we'd do instead, in order of preference: use the maker's cloud/P2P app if the recorder supports it; set up a VPN into your home network so only you can reach the recorder; and treat port forwarding as a last resort, on current, updated kit with strong passwords. Sometimes the money is genuinely better spent on a modern system than on wrestling an old one back online — our CCTV and smart home page covers what that looks like.
We do on-site visits across Bournemouth, Poole and the surrounding area to reconfigure CCTV after a broadband change, done the secure way. And if a rebuild isn't worth it, we'll say so before you spend a penny — get in touch or call 01202 775566.
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// GOOD QUESTIONS
Frequently asked
Why did my CCTV stop working when I changed broadband provider?
Because the settings your CCTV depended on lived inside the old router, and the new one doesn't have them. Port-forwarding rules are wiped when the router changes, the recorder's fixed IP address may no longer match the new router's network range, and features like UPnP are often switched off on new hubs. The cameras and recorder are usually fine — it's the network around them that changed. Cloud (P2P) systems typically just need to get back online; older port-forwarded DVRs need proper reconfiguration, ideally done a more secure way than before.
Do I need to set up port forwarding again on my new router?
Possibly — but check first whether your system actually needs it, because many don't. Modern cloud or P2P systems (Ring, Eufy, and most recent Hikvision or Dahua kits used through the maker's app) connect outwards to the vendor's servers and need no port forwarding at all; they just need the recorder or cameras back online. Only older systems reached by IP address or DDNS relied on forwarded ports. If yours is one of those, we'd honestly steer you towards the vendor's app or a VPN instead where possible, because an internet-exposed DVR is a real security risk.
Is it safe to port forward my DVR to the internet?
It's riskier than it used to be, and with an old DVR we'd say no. A forwarded port makes the recorder directly reachable from anywhere, and automated scanners probe for exposed DVRs constantly. Recorders that still receive firmware updates and have strong passwords lower the risk; older, unsupported units with known flaws are a genuine hazard and get hijacked regularly. Safer options are the maker's cloud/P2P app, which needs no open ports, or a VPN into your network. If port forwarding truly is the only option, it should be a deliberate, last-resort choice on up-to-date kit.
Why can I see my cameras at home but not when I'm out?
That pattern almost always means the cameras are healthy but unreachable from outside your network. At home, your phone finds the recorder directly on the local network; away from home, it has to come in via the internet — which is exactly the path a router change breaks. The usual causes are missing port-forwarding rules on the new router, a recorder that can't get online because its fixed IP no longer matches the new network, or double NAT if a mesh WiFi system now sits behind the provider's hub. Fix the recorder's internet access first, then the remote path.
Will my wireless cameras reconnect to the new router by themselves?
Only if the new WiFi has exactly the same name and password as the old one. Cameras store the network name (SSID) and password, so if either has changed — which it almost always has with a new provider's hub — each camera needs the new details, usually via its app's setup or reconnect option. A useful trick before your next switch: rename the new router's WiFi to match the old name and password, and most wireless cameras — along with smart plugs and doorbells — come back on their own without being touched.
Can someone come out and fix my CCTV after a broadband change?
Yes — this is a job we do regularly across Bournemouth, Poole and the surrounding area. We'll get the recorder back onto the new network, reconnect any wireless cameras, sort out mesh and double-NAT tangles, and set up remote viewing the secure way — vendor app or VPN rather than a bare open port wherever possible. If we find the recorder is too old to be safely put online, we'll tell you straight and talk through the options rather than quietly recreating a risky setup. Call 01202 775566 or use our contact page to arrange a visit.
Cameras offline since the broadband switch?
One visit usually puts everything back — set up the secure way, not the risky way. Call 01202 775566 or book a visit.
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