DHCP Static binding not working as expected??

[Sten Carlsen]

Hi

It is very likely doing what you have asked it to do.

For anybody on this list to be able to help you find out what happens
and why that  is different from what you want to happen, please post
your dhcpd.conf in its entirety with no edits (except secret keys).

First guess is that you give the fixed address inside your range of
dynamic IPs, it must be outside or you will see the below happening.


On 09/09/12 17:17, chamara samarakoon wrote:
> Hi,
>
> I am new to isc dhcp, and i am facing following situation , and need
> help to understand,
>
> Scenario.:
> I am having 3 devices called, A,B,C. On dhcp conf pool is restricted
> to *only one IP*.
> Also on dhcpd conf *static bind is enabled* for device A.
>
>
> 1.Plug device A to network -> with out issue device got IP
>
> DHCPOFFER on 51.101.0.10 to 00:20:d2:3a:51:69 via 51.101.0.1
> Commit: IP: 51.101.0.10 Mac: 0:20:d2:3a:51:69 Name:
> 51.101.0.10ClientGW: 51.101.0.1
>
> 2.Unplug device A and change the static conf MAC to B's MAC(Restart
> dhcpd server) and Plug device B
>
> No issue device B got IP,
> DHCPOFFER on 51.101.0.10 to 00:20:d2:39:24:f8 via 51.101.0.1
> Commit: IP: 51.101.0.10 Mac: 0:20:d2:39:24:f8 Name:
> 51.101.0.10ClientGW: 51.101.0.1
>
> 3. Replug the device A *with out removing device B*,
> A received the IP even though B is having it, A's IP is active and B's
> IP is not active.
>
> DHCPDISCOVER from 00:20:d2:3a:51:69 via 51.101.0.1
> <http://51.101.0.1>: network 51.101.0.0/19 <http://51.101.0.0/19>: no
> free leases
> Reclaiming abandoned lease 51.101.0.10.
> ICMP Echo reply while lease 51.101.0.10 valid.
> Abandoning IP address 51.101.0.10 <http://51.101.0.10>: pinged before
> offer
> DHCPDISCOVER from 00:20:d2:3a:51:69 via 51.101.0.1
> <http://51.101.0.1>: cancel load balance to peer XXX - no free leases
> DHCPDISCOVER from 00:20:d2:3a:51:69 via 51.101.0.1
> DHCPOFFER on 51.101.0.10 to 00:20:d2:3a:51:69 via 51.101.0.1
> Commit: IP: 51.101.0.10 Mac: 0:20:d2:3a:51:69 Name:
> 51.101.0.10ClientGW: 51.101.0.1
>
>
>
>
>
> Why this is happening, I do not want DHCPD to offer the IP to another
> device when it is bind on static file to another device.But strange
> thing is when i plug device C when only device B(*same way as device A
> plug in step 3 but this time not device A instead device C is used.*)
> is there , C naver receive a IP as i expected.Help is very much
> appreciated,What is happening with device A and B??
>
>
> Thank You,
> chamara
>
>
>
>
>
>
>
>
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>
>
>
>
> -- 
> chthsa
>
>
> _______________________________________________
> dhcp-users mailing list
> dhcp-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/dhcp-users

-- 
Best regards

Sten Carlsen

No improvements come from shouting:
       "MALE BOVINE MANURE!!!"

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