Cisco Support Community
Community Member

Problems trying to migrating ports to a new Vlan using an externar DHCP server

Hello, here is the thing. I have the following configuration in my Core Switch:

interface Vlan1
 ip address secondary
 ip address
 ip helper-address
 no ip redirects

As you see, we are using an external DHCP server for the Vlan1 and it is working:

Internet              0   3c97.0e23.3d8d  ARPA   Vlan1

Internet             0   e89a.8f77.36a0  ARPA   Vlan1
Internet             0   e89a.8f77.01ab  ARPA   Vlan1
Internet             2   001c.25de.acaa  ARPA   Vlan1
Internet             0   d8eb.97a6.30a4  ARPA   Vlan1
Internet             0   f0de.f1f1.1e06  ARPA   Vlan1
Internet             0   e89a.8f77.016f  ARPA   Vlan1
Internet             4   d0c7.89d6.3ba3  ARPA   Vlan1
Internet             0   4437.e636.7ef7  ARPA   Vlan1

But, when a try to migrate this port to a new Vlan (Vlan50), I got the following issue: 

001290: Jul 23 08:27:44.705 GMT: DHCPD: DHCPREQUEST received from client 013c.970e.233d.8d.
001291: Jul 23 08:27:44.705 GMT: DHCPD: client has moved to a new subnet.
001292: Jul 23 08:27:44.705 GMT: DHCPD: Sending DHCPNAK to client 013c.970e.233d.8d.
001293: Jul 23 08:27:44.705 GMT: DHCPD: broadcasting BOOTREPLY to client 3c97.0e23.3d8d.
001294: Jul 23 08:27:44.725 GMT: dhcp_snooping_get_ingress_port: Interface src_index 0xF
001295: Jul 23 08:27:44.725 GMT: DHCPD: DHCPDISCOVER received from client 013c.970e.233d.8d on interface Vlan50.
001296: Jul 23 08:27:44.725 GMT: DHCPD: there is no address pool for
001297: Jul 23 08:27:44.725 GMT: DHCPD: setting giaddr to
001298: Jul 23 08:27:44.725 GMT: DHCPD: BOOTREQUEST from 013c.970e.233d.8d forwarded to

Any suggestions,

Thank you in advance,

Community Member

Just to help someone who has

Just to help someone who has the same issue.

I found this on the web site:

When the server receives a DHCPREQUEST from a client in the RENEWING (or REBINDING) state, it normally grants the renewal only if the client has an unexpired lease with this server. Otherwise the server ignores the request; the server to which the client is bound should answer the client. (The only exception is normally that if a server is sure the IP address the client is asking for is inappropriate for the client, the server will send a DHCPNAK, which forces the client back to the INIT state.)

Thank you anyway

CreatePlease to create content