I am using packettracer to configure a network. The problem is that the router (that is acting as a router-on-a-stick) is not offering ip-addresses from its pool. The pc that act as the client belongs to vlan 30 and the interface fa0/1 on the switch is in acess-mode state. So no problem. And - the G0/1-interface to the router is configured as a trunk link. OK! AND - And the PC can communicate with ICMP-messages to the router if its configured static. So I do not understand why the router doesnt offer any address to the client?

When I click the DHCP-radiobutton on the pc-GUI I get the following error information:

DHCP failed. APIPA is being used

Router config for dhcp

HQ(config)#ip dhcp excluded-address
HQ(config)#ip dhcp pool LAN

And the addressing info looks like this for vlan-30 on the router:


And my config on the router for this subinterface

HQ(config-subif)#encapsulation dot1q 30
HQ(config-subif)#ip address

I add a screenshot here so you easily can see the topology of the network.

Would be greatful if someone could see why the router wont offer the ip-addresses? May it have something to do with the native vlan that is VLAN 45?


enter image description here

1 Answer 1


You've excluded all IP's available in the pool except for the network address:


indicates available IP addresses are upto and including, and

HQ(config)#ip dhcp excluded-address

Indicates that except for these addresses cannot be used. So fix that last statement so the DHCP server actually has some addresses it can assign.

  • Thanks a lot - now I can see what I did wrong - I put the subnetmask in the exluded-syntax which is wrong. Thanks!!! Commented Dec 7, 2014 at 16:48

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