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How are devices with Static IPs are getting new IPs every day.

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Last Modified: 2019-10-25
We just had an Aiphone IX system installed.   We assigned static IPs to all the devices.   We have a Samsung tablet and phone that we use to control the gates or speak to people when they push the intercom.

I have verified that the tablet and phone are set to Static.  Every day each of those devices changes the IP address.  We set it in the morning and later in the day they get a new IP.

Note:   Our DHCP has a scope of 50-200.   The IPs we have assigned are above 200.   One suggestion that we have not tried yet is to create a Reservation for those two devices.  Any thoughts on this?

I have discussed this with 4 technicians and all of them state that if an IP is assigned as static it can only be changed manually.  

We have been researching this with the company that installed it and with Aiphone.  No one can figure this out.

So my question is how is it possible for the IPs to be changing?   I know that it is not being done by anyone.   The devices are turned on in the morning and just sit on the desk until someone comes to the door or pushes the intercom.   Any ideas will be appreciated.
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nociSoftware Engineer
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Distinguished Expert 2019

Commented:
IP should only change if they are set through DHCP (and even then...  renewal might take long term pseudo statics....)...

Just setting static (aka Manual aka non dynamic)  might not be sufficient, DHCP / BOOTP needs to be disabled.  (unless there is only a switch automatic/static)...
It will never hurt to assign a reservation to the DHCP server, so in case it isn't static, then it still will get the right address.
J.R. SitmanIT Director

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Commented:
I do not have the table with me but do not recall seeing the option DHCP /BOOTP.   I did check my phone and it is not an option.
Qlemo"Batchelor", Developer and EE Topic Advisor
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Top Expert 2015

Commented:
I agree the IP should not change. Any chance you have more than one WLAN SSID set up, one with a static IP and the other with DHCP, and the mobile devices are switching between those?
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Commented:
The devices are turned on in the morning and just sit on the desk until someone comes to the door or pushes the intercom.   Any ideas will be appreciated.

You may want to setup an capture a wireshark from one of the devices when it is turned on in the morning.   Also, check the DHCP responsible for the scope that the DHCP assignment is coming from.    This really sounds like an Airphone issue as a device has to request an assignment and process that reservation when it receives it.  

Reservation assignments would help, but the device is still not honoring your settings in it for a Static assignment.,
J.R. SitmanIT Director

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Commented:
Thanks.  We are meeting with them Post Alarm today.  I'll post later.
J.R. SitmanIT Director

Author

Commented:
It infact was a Aiphone app issue.     Somehow the App was changing the IP on the device.

Thanks for helping