Repeatedly detecting address change that isn't happening

Posted on
Sat Mar 24, 2018 10:42 pm
durosity offline
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Repeatedly detecting address change that isn't happening

Or is it happening?

I've only just finally started setting up fingscan. I'm getting a recurring issue where it keeps thinking an IP address is changing:

Code: Select all
   fingscan                        IPNumber changed,  old: 192.168.1.001        ; new: 192.168.1.117         for device MAC#: 70:56:81:C5:AB:47 to switch off changed message: edit this device and select no msg
   fingscan                        MAC#:70:56:81:C5:AB:47 -- old IP: 192.168.1.117        ;  new IP number: 192.168.1.001         to switch off changed message: edit this device and select no msg
   fingscan                        MAC#:70:56:81:C5:AB:47 -- old IP: 192.168.1.001        ;  new IP number: 192.168.1.117         to switch off changed message: edit this device and select no msg


It does this for 20-30 entries in the log over the space of half an hour or so, then stops. Then at some random time later it starts again. Now 70:56:81:C5:AB:47 is the MAC address of my Airport base station and has a fixed IP of 192.168.1.001. 192.168.1.117 is that of my MacBook Pro. I’m at a loss as to why it keeps thinking this is happening. It’s not like 70:56:81:C5:AB:47 is listed in the DHCP reservation table twice, and even if it was the base station is still set to a fixed IP of .001. Any ideas?

Computer says no.

Posted on
Sat Mar 24, 2018 11:47 pm
kw123 offline
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Location: Dallas, TX

Repeatedly detecting address change that isn't happening

Experience from the past: Fing was never wrong.

Please check ~/indigo/fing.log
It shows all changes

Airport does change sometimes it’s ip number - like Apple TV , Samsung TVs ....

If you use vpn etc this can also happen.


In oder to understand it better we need more details of you network setup. Dhcp server , dns setup etc.


Sent from my iPhone using Tapatalk

Posted on
Sun Mar 25, 2018 5:05 am
durosity offline
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Re: Repeatedly detecting address change that isn't happening

Log: https://www.dropbox.com/s/afd78nk5f56eiop/fing.log?dl=0

At present my DHCP and DNS server side of things are all handled via macOS server. The airport base station also does for 2 dummy MAC addresses at 192.168.1.253/254 as you can't turn off DHCP for some weird reason. No VPN is currently in use.

Computer says no.

Posted on
Sun Mar 25, 2018 6:29 am
kw123 offline
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Location: Dallas, TX

Re: Repeatedly detecting address change that isn't happening

For these circumstance the plugin has the option in device edit to suppress the logging of these messages. But it just suppresses the messages ...

Anyway Apple devices do some strange things.




Sent from my iPhone using Tapatalk

Posted on
Sun Mar 25, 2018 4:07 pm
durosity offline
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Re: Repeatedly detecting address change that isn't happening

yeah that MAC is that of the airport base station, and it has a static IP of 192.168.1.1 and the DHCP server also has it assigned to that same IP just in case. It’s very intermittent in its nature. Next time I see it happening live I’m gonna run Fing on an old iPhone (where it could still scan MAC addresses) and see if it does the same.

Computer says no.

Posted on
Tue Oct 23, 2018 2:20 am
zaiks offline
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Joined: May 19, 2016

Re: Repeatedly detecting address change that isn't happening

durosity - have you managed to find solution about the changing IP address issue. My Airport Extreme gets also confused, but its random wather with one Apple TV or PS4

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