Smart Hub 7 Plus unable to assign static IP addresses

[Finnerz]

Hi,

I'm struggling to assign devices on my home network static IP addresses. 

Some devices seem to work fine but others no matter what I try they just wont save. 

I read somewhere on the forums that the router/hub wont re-use previopusly assigned IP addresses, is this true?

Am I out of luck?

[JimM11]

@Finnerz You are correct, if an IP has been assigned previously to a device that is offline etc, then that IP is not available to be assigned again, the DHCP server remembers that address and you will not be able to use it.

You can if you wish look see, note them all to start with then re-structure it all again, you will have to plan it all before you start and it can be done for sure. 

[XRaySpeX]

@JimM11 : Yes, you can! All you need to do is change the IP addy. last octet & "Always use this IP address:" = YES & Save. In the Network map you'll end up with 2 devices with the same IP, 1 of which is offline.

[Finnerz]

Unfortunately this doesnt work for me and trust me I've tried. 🙂

All I get when I do this is N/A in the IP address.

[Finnerz]

Its odd we cant remove an offline device to free up its IP address. I wonder what happens when all 199 addresses are taken up (granted thats a lot devices) when using range 192.168.1.54 - 192.168.1.253. 

[JimM11]

@Finnerz Going to leave you in the hands off @XRaySpeX , he says it all works, that as you say EE hubs will never have the ability to support so many devices, you will find that on the Forum also if you go look. 

[baron75mk3]

I dont know how much help this would be but you do know you dont have to assign IPs router side ?, just set up your static IP device side if you do this its exactly the same thing it wont move , its how i have done mine its what i usually do , problem i had with assigning in router was it stopped logging data usage so i just do it device side at end of the day all you want is the IP to never change if you set up static Ip device side it will have the same effect.

Problem with used IPs are as stated if the device is disconnected the router remembers it i have encountered same thing in past & just pinned & reset router to factory defaults & started again 1 device at a time sucks but it will clear everything.

[Denzel99]

Essentially, @baron75mk3 is right but it’s not quite that simple.  There are two ways to set an address that doesn’t change.

1)  A “static address” is set on the device itself and is nothing to do with DHCP.  For that reason, it has to be outside of the address range that DHCP is issuing, otherwise it causes chaos that brings a network to a standstill.

2) A “reserved address”.  These are set by DHCP and are linked to the MAC address of the device.  As such they should be within the range being issued by DHCP.  This is what is set by “Always use this address”.

Reserved addresses are notoriously flaky.  I had one at home that worked fine for several years, then it suddenly started playing silly-so-and-so’s, for no obvious reason.  One place I worked would not allow reserved addresses for that reason.  A couple of years later, I worked for a different company that always used reserved addresses and never had a problem.

Personally, I’d change the address range on the hub to create a range for static addresses and then set them on the devices.

[Denzel99]

In fact, a thought has just occurred.

You say you are only having problems with some devices.  These devices are not using MAC randomisation are they?  That will screw-up the reservation, as they will be seen by DHCP as a different device each time.

[JimM11]

@Denzel99 Static address with the DHCP server get's assigned but you have to watch what can be done. See Linked when cleared.

Allows the structured IP network to be created.