Unwanted DHCP Clients Requests ISC-DHCP-SERVER

[Steven Carr]

It may also indicate that there is VLAN/broadcast domain leakage if
you are seeing broadcast packets from other networks on your network.


On 17 May 2013 17:21, Steven Carr <sjcarr at gmail.com> wrote:
> Speak to your network administrator and tell them to remove the IP
> helper for the networks you do not provide DHCP for.
>
> From DHCP just remove the network scopes as well, it makes no
> difference if they are defined as the physical network is going to
> push the DHCP requests to your DHCP server anyway, so until the
> network admin changes the network config you will just have to ignore
> the unwanted requests and ignore them in the logs.
>
>
> On 17 May 2013 17:03, Prabhpal S. Mavi <prabhpal at digital-infotech.net> wrote:
>> Dear DHCP Gurus
>>
>> i have full of log with unwanted dhcp client requests that i don't suppose
>> to receive. i applied following solution but did not help. anyone have
>> idea to stop them ?
>>
>>
>> subnet 192.168.3.0 netmask 255.255.255.0 {
>> range 192.168.3.100;
>> ignore booting;
>> }
>> subnet 192.168.4.0 netmask 255.255.255.0 {
>> range 192.168.4.100;
>> ignore booting;
>> }
>>
>>
>> i have thousands of this requests.
>>
>> May 17 15:58:18 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:18 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:21 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:21 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:22 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:22 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:22 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:22 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:23 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:23 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:26 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:26 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:26 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:26 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:29 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:58:29 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:58:59 captive dhcpd: DHCPREQUEST for 192.168.4.87 from
>> 7c:11:be:63:32:d2 via eth0: wrong network.
>> May 17 15:58:59 captive dhcpd: DHCPNAK on 192.168.4.87 to
>> 7c:11:be:63:32:d2 via eth0
>> May 17 15:59:01 captive dhcpd: DHCPREQUEST for 192.168.4.87
>> (192.168.3.133) from 7c:11:be:63:32:d2 via eth0: wrong network.
>> May 17 15:59:01 captive dhcpd: DHCPNAK on 192.168.4.87 to
>> 7c:11:be:63:32:d2 via eth0
>> May 17 15:59:26 captive dhcpd: DHCPREQUEST for 192.168.4.235
>> (192.168.3.133) from 00:16:44:63:4b:e1 via eth0: wrong network.
>> May 17 15:59:26 captive dhcpd: DHCPNAK on 192.168.4.235 to
>> 00:16:44:63:4b:e1 via eth0
>> May 17 15:59:32 captive dhcpd: DHCPINFORM from 192.168.4.235 via eth0
>> May 17 15:59:32 captive dhcpd: DHCPACK to 192.168.4.235
>> (00:16:44:63:4b:e1) via eth0
>>
>> Thanks
>>
>>
>>
>>
>>
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