DHCP Manually assigned IP not used

[Jeje2]

Just noticed that a device I have manually assigned in the Manually Assigned IP around the DHCP list isn't using the assigned IP, even though MAC address is right...

Looked at assigned DHCP IP addresses under system log and noticed this one device on "wrong" IP-address compared to what I have specified in the DHCP manual list...
So now I'm confused - why isn't it using the assigned IP?
(And this MAC and IP binding configuration I have done weeks ago...)
Using RT-BE86U with newest asuswrt FW v. 3.0.0.6.102_39112

 

[jksmurf]

why isn't it using the assigned IP?

Funny, I think this has happened to all of us at some stage.
IIRC, it should get the manual assigment first, then DHCPs are assigned later.

So, quick answer, without looking at any logs, a couple of reasons might be:

1. The device has a static IP assigned on the Device (but you would probably remember this; nonethless, maybe check)?
2. You assigned the device its manual IP some time ago, after it already had got a DHCP assigned address. Since then, have you restarted (a) the device and (b) the Router ?
   
   [or failing (b), that at least restarted dnsmasq? From the SSH CMD Line: service restart_dnsmasq ] ?
   
   
3. Even though MAC address is correct, sometimes it isn't i.e. that errant 0 vs O really gets you. Pays to double check?

 

[Jeje2]

Well it's my wife work-laptop and she hates to restart it as has a lot of programs constantly open to do her job... So technically I can't out rule that she wouldn't have restarted (been to the office, even this week) her laptop.

But I still find it strange as I did move other devices desired IP's when rebuilt the Manually assigned MAC to IP list in DHCP server after last FW-update with full factory rest .... and for other devices they immediately got the new desired ip's into usage.

 

[jksmurf]

So technically I can't out rule that she wouldn't have restarted

You’ll never know until you try…

 

[Ripshod]

Try changing the manually assigned ip to the ip it's currently using. Simples!
We can spend weeks and weeks getting something to work the way we want, but a small change and a reasonable amount of flexibility we can make it work in a suitable manner.

 

[jksmurf]

But I still find it strange as I did move other devices desired IP's when rebuilt the Manually assigned MAC to IP list in DHCP server after last FW-update with full factory rest .... and for other devices they immediately got the new desired ip's into usage.

This morning I was fiddling around with DHCP assignments and my HA Server was given a Dynamic IP address by the Router.

I then set a manual IP on the router for the HA Server and rebooted the router. The HA Server steadfastly refused to be accessible on the newly assigned IP. It was accessible on the DHCP one.

However when I then rebooted the HA Servee it became accessible on the manually assigned address. I’ve had this happen before with other devices. So that’s my 2c …

 

[bennor]

Just noticed that a device I have manually assigned in the Manually Assigned IP around the DHCP list isn't using the assigned IP, even though MAC address is right...

What is the device that has the manual address assigned but isn't using it? Some devices, particularly cell phones, can now randomize their MAC address. You would need to go into that device's settings and disable the MAC randomization option.

Otherwise power down the affected client device (and remove power if possible from it for a short period of time) then power that device back on and see if it pulls the correct manual IP reservation.

 

[Ripshod]

Otherwise power down the affected client device (and remove power if possible from it for a short period of time) then power that device back on and see if it pulls the correct manual IP reservation.

OP has a wife

Well it's my wife work-laptop and she hates to restart it as has a lot of programs constantly open to do her job...

 

[degrub]

If she has admin access rights or an admin account, try a MSDOS CMD window and use
IPCONFIG /all
to see what the current config is. Also, check the LAN/wifi adapter driver config to see if a manual address has been set up.
Then , if not correct IP address and not manual address, type
IPCONFIG /release

you may want to unplug her laptop LAN cable or turn the laptop wifi radios off then on.
Run the /all again and see what happened. If nothing,
then
IPCONFIG /renew

use the /all switch to see if the updated IP address from the router reservation took effect.

 

[jzchen]

No space ipconfig /renew ....

 

[Jeje2]

IPCONFIG /all
IPCONFIG / renew

Ipconfig commands are very familiar with - did run Windows servers for 10+ years at work. Luckily nowadays not anymore have to be sysadmin... (IIRC last windows server I was responsible of was shut down some 10-12 years ago...)
The /all can anyone do - even I do it on my work-laptop (And have much stricter policies at my work than wife has)
I just always have preferred to execeute first /release to unsure IP leases are released before execute /renew. (At least back in the days /renew didn't work to 100%, so /release was a working solution...)

That said - not planning on going to reset & renew her work laptop...

 

[jzchen]

@degrub accidentally had a space "/ renew" and I did not want you to have an angry wife if you just cut and paste. I was taught these by a friend in college and always appreciated learning about them. I agree release first, not sure if /renew switch works directly...