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DHCP server issue - authoritative pool doesn't send NACK to client

Occasional Visitor

DHCP server issue - authoritative pool doesn't send NACK to client

Hello everyone

I have very frustrating issue with HPE 5412zl2 or 2930F switch. I have DHCP server configured on switch. Server assigns IP address to clients but have strange issue. When client connects/moves from another networks (have cached old IP) clients sends DHCPREQUEST requesting his old IP address. When DHCP pool is authoritative, server should send DHCPNACK to endpoint and force client to obtain new/proper IP address from his pool. Quote from RFC: "If the DHCP server detects that the client is on the wrong net ... then the server SHOULD send a DHCPNAK message to the client". But on HPE switch this never happes, despite authortative option is set on pool. Clients send about 10-15 DHCPREQUESTS and finally obtain proper address after about 1-2 minutes. I think that is a bug, any other DHCP server which I have on the network works correctly and send NACK packet. I try several firmware 16.05, 16.06 and 16.07 unsuccessfully. Can anyone help me configure DHCP server on this device? I need DHCP server resides on switch for guest network purpose.

Below is my configuration:

dhcp-server pool GUEST
default-router ""
dns-server ","

vlan 98
exit dhcp-server enable

I receive the following information in dhcp debug log:

DHCPS eDhcpdProto:DHCPREQUEST for 192.168.0.x from aa:bb:cc:dd:ee:ff via vlan98: ignored (not authoritative).

 Notice that endpoint is directly assigned to VLAN 98 so ip-helper isn't necessary!

Thanks in advace