Strange DHCP Server Behavior

[darkwizard06]

Good day.
 

I have encountered a strange behavior in my network. My Router is the only DHCP server on my network, and there are 15 connected computers with DHCP Reservation each.  One day I've decided to temporarily disconnect one computer and I removed it from the DHCP Reservation and obviously it shouldn't connect to its reserved ip which is x.x.x.160 . After 4 days, I've connected the aforementioned computer and I am expecting that the DHCP server should assign it on x.x.x.100 , but the ip address remains the same (x.x.x.160).
 

PS: DHCP Lease is set to 12 hours.
 

Is it strange? or Is it normal? Can you please enlighten me about it.
 

Thank you very much.

[CiscoFan]

Your computer probably sent the server a packet saying to update it's lease for x.x.x.160.

This is what it looks like when it renews the lease for that address.

[darkwizard06]

10 hours ago, droidrzrlover said:

Your computer probably sent the server a packet saying to update it's lease for x.x.x.160.

This is what it looks like when it renews the lease for that address.

So it means my computer still remembers its assigned DHCP IP address even though it was powered off 4 days after disconnection from the network?  I am still thinking until now.

[leadeater]

24 minutes ago, darkwizard06 said:

So it means my computer still remembers its assigned DHCP IP address even though it was powered off 4 days after disconnection from the network?  I am still thinking until now.

Yes that is correct, computers do remember their last assigned DHCP IP Address even after a reboot or being shut down. Often you want a computer to always get the same IP Address if possible.

 

Open up command prompt and type 'ipconfig /release' then 'ipconfig /renew'. The release switch makes the computer forget it's last assigned IP Address and ask for a fresh one.

[darkwizard06]

11 minutes ago, leadeater said:

Yes that is correct, computers do remember their last assigned DHCP IP Address even after a reboot or being shut down. Often you want a computer to always get the same IP Address if possible.

 

Open up command prompt and type 'ipconfig /release' then 'ipconfig /renew'. The release switch makes the computer forget it's last assigned IP Address and ask for a fresh one.

I see. haha now I know. So it is normal.  By the way does it apply to android os too?

[brwainer]

7 minutes ago, darkwizard06 said:

I see. haha now I know. So it is normal.  By the way does it apply to android os too?

I can tell you that iOS remembers it's last IP for each wireless it connects to, unless you completely remove the wireless network completely. I don't know what Android does.