One Camera has 2 different IP addresses in same subnet?

[Pseudomizer]

Hi guys,

I purchased an outdoor cam 6 months ago on Amazon "5MP PTZ Security Camera Outdoor, CKK 5MP Wireless Pan Tilt Zoom (4xDigital) IP Camera with 64GB SD Card Human Detection, 2 Way Audio, Color Night Vision, Floodlight & Siren Alarm". This camera is now no longer available.

My UDM Pro recognizes this camera as "Reolink C2-Pro" and using the MAC address I assigned a fixed IP address when the DHCP requests comes in with IP address of x.x.x.159. Using BlueIris, the camera is detected as a Cantonk compatible camera.

However, the same camera is also available on my network under x.x.x.10. I can ping it, I can have BlueIris connect to it and it shows a video stream. My UDM Pro though doesn't show the x.x.x.10 as connected under the clients list. Having different IP addresses on one network is possible, but usually in different networks or more precise other subnets. Having a camera in e.g. x.x.1.159 and x.x.5.10 would make sense or VPNs. I don't use VPNs and they are in the same class C 255.255.255.0 subnet. If this network card has one MAC address, my UDM Pro would assign the x.x.x.159 IP address to it.

How is it possible that the SAME camera is reachable on 2 different IP addresses in the same subnet please? Does anybody have an explanation for this? Why does my UDM pro doesn't list this IP address?

Thanks in advance.

 

[Pseudomizer]

I stand corrected. I had 3 cameras in BlueIris and I added a 4th one using x.x.x.159 showing the same stream as x.x.x.10. Now, I reopened BlueIris and now I have 4 cameras with 2 of them having the same stream and both of them show x.x.x.10. My x.x.x.159 somehow got changed to x.x.x.10. I am even more confused now as my UDM Pro still doesn't show x.x.x.10 as connected and the ONLY camera matching has the IP address x.x.x.159.

Can somebody make sense of this?

 

[Flintstone61]

Class C LAN IP addresses: we all have the same pool of addresses as you, non-disclosure of the first 3 Octets doesnt help. only your External IP address on the Internet facing side is critical.

 

[Pseudomizer]

Sure. NAT behind a router with 192.168.0.0/24. And how does this help you please to potentially address my weird issue?

 

[Flintstone61]

Ok, I'm not a Ubiquiti experienced person......So I can't authoritatvely speak to the issue.
I was thinking maybe you had a cam which was previously used on a NVR and somebody made it Static in the 10.10.xx network.

 

[Flintstone61]

Oh yawn sorry, after re-reading your post you explained the Ip address scheme. ....It's a head scratcher for sure, hopefully some has run into this before....I have had some trouble adding certain new cams to Blue iris or NVR's, and eventually got things straight, but not this problem.

 

[Pseudomizer]

Fair point. Yeah, I am fairly technical myself and I have installed many systems in my life in data centers but that's a weird phenomenon.

 

[TonyR]

FWIW, some Amcrest (Dahua OEM) cameras such as the IP2M-841 can have 2 IP's in the same subnet; 1 wired and 1 wireless.

To add to your IP mix, since version 5.6.2.0 of Sept. 23, 2022 Blue Iris can find a cam by using its MAC address, not its IP. That feature can be disabled and BI made to use only the IP as before.

 

[paul@austins.tv]

I recall from some years ago that a old Hikvision IP camera had two IP addresses. One for the LAN connection and one for the WiFi. I turned off the WiFi connection as it wasn't required and the second IP address disappeared.

 

[Pseudomizer]

The app doesn't show any IP address from the supplier. I think I will do a wire trace and see what this cam sends to where. I am suspicious now....

 

[Pseudomizer]

FWIW, some Amcrest (Dahua OEM) cameras such as the IP2M-841 can have 2 IP's in the same subnet; 1 wired and 1 wireless.

To add to your IP mix, since version 5.6.2.0 of Sept. 23, 2022 Blue Iris can find a cam by using its MAC address, not its IP. That feature can be disabled and BI made to use only the IP as before.

Correct, that cameras have sometimes 2 IP addresses one for Wifi and one for wired but they have different MAC addresses. Even if they use one MAC address aka virtual MAC address for Wifi and Ethernet, they need to disable one of them when the other is active per RFC spec. Assuming they do multi-homing or even multi-casting, they still have to follow the rules.

With all that said, following the standards of IEEE and RFCs for networking (also nicely summarized here MAC address - Wikipedia) show, that one MAC address should only have one IP address per subnet. Any ARP broadcast (as outlined in the spec) should only get one and only one response. I will dig deeper here as this is very weird and if they modified their IP stack, what else did they do?

 

[TonyR]

Correct, that cameras have sometimes 2 IP addresses one for Wifi and one for wired but they have different MAC addresses.

True, but I didn't get that from your first post, just the issue of "2 different IP addresses in the same subnet ."

 

[Pseudomizer]

I am not using "wired". I just using Wifi, so it should only have one IP address assigned to one MAC address but I have two now.

 

[TonyR]

I am not using "wired". I just using Wifi, so it should only have one IP address assigned to one MAC address but I have two now.

Got it.

 

[Flintstone61]

So your not powering the Cam Via Poe/Cat5? right?
Might be the reason it's no longer available or a White label cast off is that its got janky hardware.....
It's fucking Goofy.
maybe try another cam.
I have a couple " live and learn" cams in a box over here.

 

[Pseudomizer]

I have installed over 40 cams over the last 15 years as I lived in different locations and 6 different brands.

This time I tried something new where the cam 360 motion detection human detection and it follows you once a human is recognized.

It also has lights build in but that feature is mah meaning it has to recognize humans to turn on. If no human then no light. What if you want any motion to turn lights on? That is not an option as the manufacturer replied to me already.

No, I am not using for this outdoor cam PoE. Straight power and WiFi only.

 

[TonyR]

Interesting ==>> In ARP spoofing is it two MAC mapping to one IP address OR two IP mapping to one MAC address?

 

[Pseudomizer]

I would love to be able to answer that but my UDM pro doesn't even list the 159 IP address as a client but I can ping it and use it in BlueIris. That's why I said I might just use Wireshark and see what's going.

 

[Mike A.]

What do you see if you run "arp /a" in a command box?

 

[JDman]

Had the same problem with some icsee pro cameras with a different NVR package. I solved it by blocking the secondary MAC address at the router so it couldn't get an IP.