DHCPDISCOVER from MAC address of switches DELL N1524

Hi dear,

We have a lot of switchs N1524 and all of them have fixed IP address in vlan60. My DHCP server (FreeBSD) is receiving DHCPDISCOVER from MAC address of the switchs DELL.

At this company, we have switches Cisco and we dont have problems with these switchs.

Switch DELL:

#show ip int

Default Gateway................................ XXX.XXX.XXX.253
L3 MAC Address................................. YYYY.YYYY.YYYY

Routing Interfaces:

Interface    State   IP Address      IP Mask         Method

----------   -----   --------------- --------------- -------

Vl1          Down    0.0.0.0         0.0.0.0         None

Vl60         Up      XXX.XXX.XXX.102   255.255.255.0   Manual

#show version

unit active backup current-active next-active
---- ----------- ----------- -------------- --------------
1 6.3.3.8 6.2.6.6 6.3.3.8 6.3.3.8

===

Log DHCP FreeBSD:

Oct 23 13:52:05 -gw001 dhcpd: DHCPDISCOVER from YYYY.YYYY.YYYY via vlan60
Oct 23 13:52:10 -gw001 dhcpd: DHCPDISCOVER from YYYY.YYYY.YYYY via vlan60
Oct 23 13:52:19 -gw001 dhcpd: DHCPDISCOVER from YYYY.YYYY.YYYY via vlan60
Oct 23 13:52:20 -gw001 dhcpd: DHCPDISCOVER from YYYY.YYYY.YYYY via vlan60
Oct 23 13:52:22 -gw001 dhcpd: DHCPDISCOVER from YYYY.YYYY.YYYY via vlan60

When my DHCP server receive a DHCPDISCOVER it gives a DHCPOFFER and allocate an IP on lease. Would anyone help me please?

Obs.: the DELL switch dont send REQUEST only DISCOVER

Thanks in advice.