FiOS router coming online interrupts camera feeds... why?

[ExTechjunkie]

Tonight my usually bulletproof FiOS service was interrupted when a firmware update was pushed to my router. After twice restarting the router, I finally had to power cycle the ONT to restore internet access after the event. That aside, I noticed something I can't reconcile. Both times that the router powered back up, both my NVR and my Blue Iris PC lost the feed from my cameras. All the devices are static IP and all are interconnected via switches that are not part of the FiOS router. The router only provides internet connection to my home network from one of its switch ports to one of the ports on a secondary switch to which everything else is connected. I checked the logs of the managed POE switch that the cameras and NVR are directly connected to and it did not reboot. I knew that already because the video interruption on each of the channels was for less time than it takes for any of the POE cams to restart and the NVR or Blue Iris to reconnect. So... being that the router's built-in switch is not in the path between the cameras and the NVR or PC, why then does the router starting up interrupt the feed?

 

[TonyR]

Wow...that is strange.

Wouldn't unplugging that cable from the "...router...switch port to one of the ports on a secondary switch..." replicate it somewhat?
What happens when you do that?

I get Internet from my AT&T Fixed Wireless's modem/router (Pace 5268AC) like that as well (one of it's LAN ports runs to one of my switches) and I lose no cam feeds to Blue Iris if I unplug that cable OR re-boot the modem and that makes sense to me.

 

[The Automation Guy]

First, I am not a network expert. As such, I may not fully understand the architecture correctly.

That being said, unless your network switch is a layer 3 switch set up to handle the routing of your CCTV network, the router is still responsible for your network's routing tables (even when using static IP addresses). As such, when the router is shut down and those tables deleted, devices on the network may have trouble communicating with other devices. At least that is how I understand it.

 

[ExTechjunkie]

First, I am not a network expert. As such, I may not fully understand the architecture correctly.

That being said, unless your network switch is a layer 3 switch set up to handle the routing of your CCTV network, the router is still responsible for your network's routing tables (even when using static IP addresses). As such, when the router is shut down and those tables deleted, devices on the network may have trouble communicating with other devices. At least that is how I understand it.

I think you might have hit the nail on the head. At least the part about the function that the router is performing. I’ll look into forcing a static route independent of that router. Thanks.

 

[srvfan]

I think you might have hit the nail on the head. At least the part about the function that the router is performing. I’ll look into forcing a static route independent of that router. Thanks.

This is exactly my problem as well. At the present time, I have my router in front of my network and switches. Whenever I lose connectivity to the router, it shuts down the whole network (VLANs) as the router keeps everything up. Poor design on my part.
This is why I'm reviewing alternatives to my current setup to include routes separate from the router itself as you mentioned.

 

[alastairstevenson]

I’ll look into forcing a static route independent of that router.

Does this mean that you have more than one subnet configured in your LAN, and the router is providing the routing interface between them?

If so, some devices, depending on how their network stack behaves, may still forward their traffic via the router, as opposed to forwarding it to the gateway address that is configured in the router-defined static route after the routing query is responded to.
If the router IP address is the only gateway defined in the static route, then all inter-subnet traffic will flow through it.

 

[mat200]

Tonight my usually bulletproof FiOS service was interrupted when a firmware update was pushed to my router. After twice restarting the router, I finally had to power cycle the ONT to restore internet access after the event. That aside, I noticed something I can't reconcile. Both times that the router powered back up, both my NVR and my Blue Iris PC lost the feed from my cameras. All the devices are static IP and all are interconnected via switches that are not part of the FiOS router. The router only provides internet connection to my home network from one of its switch ports to one of the ports on a secondary switch to which everything else is connected. I checked the logs of the managed POE switch that the cameras and NVR are directly connected to and it did not reboot. I knew that already because the video interruption on each of the channels was for less time than it takes for any of the POE cams to restart and the NVR or Blue Iris to reconnect. So... being that the router's built-in switch is not in the path between the cameras and the NVR or PC, why then does the router starting up interrupt the feed?

Static IPs on cameras .. hmmm ..

What else could it be? ...

 

[ExTechjunkie]

Does this mean that you have more than one subnet configured in your LAN, and the router is providing the routing interface between them?

If so, some devices, depending on how their network stack behaves, may still forward their traffic via the router, as opposed to forwarding it to the gateway address that is configured in the router-defined static route after the routing query is responded to.
If the router IP address is the only gateway defined in the static route, then all inter-subnet traffic will flow through it.

This is what has me confused… it’s all intrasubnet traffic. The ip-cams, NVR and blur Iris pc are all on the same subnet. What’s more is that I can unplug the Ethernet cable from the router and everything keeps working. Likewise if I unplug the routers power cable. The interruption only occurs when the router starts up.

 

[alastairstevenson]

Hmm... that's certainly odd. The devices should then just depend on ARP for layer 2 traffic.
It's hard to understand how the router would interfere with that unless it's managing to clear devices ARP caches on its startup. Odd.

 

[TonyR]

Agree it's strange....my router assigns IP's to my DHCP devices, Blue Iris and cam IP's are static and could care less if the router is on, off or rebooting...all on 192.168.1.XXX subnet, gate way is 192.168.1.254.

Did you choose IP's for your static devices that are OUTSIDE of the router's DHCP pool?

 

[ExTechjunkie]

Did you choose IP's for your static devices that are OUTSIDE of the router's DHCP pool?

Yes. As an added measure, I also have static assignment of those addresses to those MACs in the router, in case DHCP gets enabled on the devices. Internet access is blocked for the cams’ addresses as well, but that shouldn’t matter to the nvr or the pc, which added the cams by IP address.

 

[bp2008]

My best guess is the router coming online causes some devices to refresh their DHCP lease which causes a momentary loss of connectivity.

 

[alastairstevenson]

My best guess is the router coming online causes some devices to refresh their DHCP lease which causes a momentary loss of connectivity.

In which case removing the DHCP reservations in the router configuration might be an interesting experiment to determine if this is the underlying cause.
The static IP addresses of the cameras should persist independently.

DHCP leases are normally periodically renewed prior to expiry under normal conditions - we don't see any loss of connectivity when this takes place.

 

[ExTechjunkie]

In which case removing the DHCP reservations in the router configuration might be an interesting experiment to determine if this is the underlying cause.
The static IP addresses of the cameras should persist independently.

DHCP leases are normally periodically renewed prior to expiry under normal conditions - we don't see any loss of connectivity when this takes place.

Agreed. I don’t think that’s it either.
Considering how infrequently my router gets rebooted (firmware updates every few years), this isn’t an issue that warrants the effort it might take to solve it. It’s more of a puzzle, really.

 

[mat200]

well, only thing I can think of is the router sends some sort of multicast signal that messes with the LAN ..

 

[tech_junkie]

Tonight my usually bulletproof FiOS service was interrupted when a firmware update was pushed to my router. After twice restarting the router, I finally had to power cycle the ONT to restore internet access after the event. That aside, I noticed something I can't reconcile. Both times that the router powered back up, both my NVR and my Blue Iris PC lost the feed from my cameras. All the devices are static IP and all are interconnected via switches that are not part of the FiOS router. The router only provides internet connection to my home network from one of its switch ports to one of the ports on a secondary switch to which everything else is connected. I checked the logs of the managed POE switch that the cameras and NVR are directly connected to and it did not reboot. I knew that already because the video interruption on each of the channels was for less time than it takes for any of the POE cams to restart and the NVR or Blue Iris to reconnect. So... being that the router's built-in switch is not in the path between the cameras and the NVR or PC, why then does the router starting up interrupt the feed?

It sounds like your computer you are using for the Blue Iris NVR program has only one network interface.
So any change with the router will dump the computer's ARP table.

Off topic: I've been thinking of trying Blue Irus. But of course setting it up on a computer that has two ethernet ports: one for internet the other for the cam network. To avoid network issues like above and set the computer up to be more like an NVR and keep my cameras seperate from the local internet network.

 

[ExTechjunkie]

It sounds like your computer you are using for the Blue Iris NVR program has only one network interface.
So any change with the router will dump the computer's ARP table.

My NVR only has the one network port and I need to access it from the internet, so if you’re right, then this is unavoidable.