Weird Thing Happen...Not Even Sure I Can Explain It

[ARAMP1]

I just had the oddest thing happen with Blue Iris. A little background with how I have things organized is necessary...

I'm using pfSense for my router and all my cameras are on a dedicated VLAN (VLAN30), so I've given them all local addresses that are 192.168.30.XX. I've organized the cameras by which side of the house they're on, so the fronts are 192.168.30.1X, one side is 192.168.30.2X, etc. When I add a new camera to my setup, I'll hook it up right to my rack in my network closet and assign it the local address of 192.168.30.99. That way, I can go into the UI and configure it, but it still has all the firewall rules, etc. Then, when I mount it on the side of the house, I'll change the IP address then add that IP address in Blue Iris.

So anyway, I've been upgrading cameras on the front of the house and the old cameras on the front are slowly going to replace the even older cameras in the back. I reset this Hikvision camera back to default with the Hikvision SADP tool and started to adjust settings for how I might use it but got called into work so I inadvertently left it plugged into my switch in my rack. I return from work this evening and find that one of my side cameras is now showing the inside of the network closet in Blue Iris. It somehow switched over to 192.168.30.99 in Camera Settings->Video->Network IP. I've never used 192.168.30.99 in Blue Iris. I switched it back to the correct IP address of the Dahua camera that is actually on the side of my house. I'm surprised the Stream Profiles worked because it still had the Dahua main and substream in there. I've never seen this before or even know how this might have happened.

 

[IAmATeaf]

This might be related to the recent MAC address mapping functionality that was added a few versions back.

Doesn’t affect me as all my cams are assigned a static IP but from what I’ve read if the cam has a DHCP assigned address BI will make a bit of its MAC address and if the cam then goes offline it will use (I assume and ARP call) to reset the IP address of the cam based upon its MAC.

Not too sure how it might affect you as ti does sound like you gave your cam a static IP but if you look in logs dialog at the cam info there should be a column for MAC. All my cams are blank but if you have a cam listed there with a MAC then in theory BI is watching it

 

[ARAMP1]

You may be on to it. Definitely gave the camera a static IP through Hikvisions SADP tool when it was initialized. But, since the camera was moved from the side of the house a couple months ago, I'm not sure which position I took it down from. (I have about 5 of them sitting in my garage) BI may have put it back in the same, original place somehow using the MAC. Weird man.

 

[tech_junkie]

So anyway, I've been upgrading cameras on the front of the house and the old cameras on the front are slowly going to replace the even older cameras in the back. I reset this Hikvision camera back to default with the Hikvision SADP tool and started to adjust settings for how I might use it but got called into work so I inadvertently left it plugged into my switch in my rack. I return from work this evening and find that one of my side cameras is now showing the inside of the network closet in Blue Iris. It somehow switched over to 192.168.30.99 in Camera Settings->Video->Network IP. I've never used 192.168.30.99 in Blue Iris. I switched it back to the correct IP address of the Dahua camera that is actually on the side of my house. I'm surprised the Stream Profiles worked because it still had the Dahua main and substream in there. I've never seen this before or even know how this might have happened.

The old static address was in the ARP table of a static addressed device on the network. After some period of time (usually every 2 hrs) the router updates its ARP table from static connections in the background. Then when the router saw the mac address not having the same ip it assigned it the ip and mitigate the new ip address. If you have a mac address scanner, it will show both IPs assigned to this mac address.

 

[ARAMP1]

The old static address was in the ARP table of a static addressed device on the network. After some period of time (usually every 2 hrs) the router updates its ARP table from static connections in the background. Then when the router saw the mac address not having the same ip it assigned it the ip and mitigate the new ip address. If you have a mac address scanner, it will show both IPs assigned to this mac address.

Makes sense, however this camera has been sitting in the garage for a couple months. I just checked my ARP table and everything seems to be on the up-and-up. I've repurposed 4 of these cameras to the back yard now and everything has been good prior. I'm guessing if/when I do add it to BI and change the IP address, it'll probably stay and be good to go.

 

[tech_junkie]

Makes sense, however this camera has been sitting in the garage for a couple months. I just checked my ARP table and everything seems to be on the up-and-up. I've repurposed 4 of these cameras to the back yard now and everything has been good prior. I'm guessing if/when I do add it to BI and change the IP address, it'll probably stay and be good to go.

Arp tables in a static connection are persistent and don't change unless the MAC address receives a new ip in the network. And some devices don't flush this table on powered down /or reboot. And it could be any static device (computer, printer, camera, etc) that might have the record.
Most people don't ever encounter this behavior because they change the static ip before the ARP round robin update on the network. Which the other devices will update their table once they see that mac address with a different network ip.

 

[Mike A.]

Probably is related to whatever BI now is trying to do with IP addresses. Since updating to the last few versions, I've seen it change the IPs for several of my existing cams. In an earlier of these versions, it wouldn't let me change the IP for a new cam that I'd copied from another. Kept changing it back and treating it as if it were a clone even though not set up as such. All of mine are static too.

 

[bp2008]

From the BI help file:

5.6.2 - September 23, 2022

The Camera Discovery window now finds MAC addresses along with IP addresses. You also
have the option of using the previous ONVIF discovery, or the new full LAN IP and port
scan. With this, it should no longer be necessary to use the external website service
Advanced Port Scanner to search your network.

LAN cameras now automatically pull MAC addresses and they are displayed on the Status/
Cameras page.

If a camera’s MAC was previously determined and the camera experiences connectivity
issues, the software with automatically scan the LAN in order to detect an IP address
change. If a new address is found, it will be adopted and posted to Status/Log. This
provides protection against IP address changes when DHCP is left active on a camera.

 

[bp2008]

The question is, why would BI remap one of your Dahua cameras to .99 when it is in fact a Hikvision camera that possesses that address? Seems like something is probably bugged somewhere.

Unless you recently had that Dahua camera occupying the .99 address. Then BI could have changed that camera's configuration to point at .99 at a time when it was the "correct" thing to do. And if you switched the .99 address over from the Dahua to the Hikvision camera quickly enough, Blue Iris may not have seen the address as being offline long enough to do its normal address change detection.

E.g. this seems like a probable sequence of events:

1) You change the IP of the Dahua camera from .1X to .99.
2) Blue Iris detects the camera is offline, finds the new address.
3) Maybe you change the IP of the Dahua camera from .99 to something else. Or maybe you don't. Doesn't actually matter.
4) You unplug the Dahua camera before Blue Iris detects another address change.
5) You add a new Hikvision camera with address .99.
6) Blue Iris still thinks .99 is a Dahua camera. I think Hikvision's RTSP server is very tolerant of unrecognized RTSP URLs, so it delivers a video stream when asked.

Anyway if you never did Step 1 of that sequence, then something definitely went haywire in Blue Iris's IP change detection.