DHCP not working inside a VLAN

[Frank Sinatra]

I have a very simple setup. A Netgear router that is connected to WAN and has four ports. If I connect a PC to any port, I get an IP from DHCP (192.168.10.0/24) and the internet is also working. 

What I want to do is to extend this to a Cisco switch. On the switch, I have created VLAN 10 and assigned the ports 1-10 to that VLAN. Port 1 is connected to the Netgear as a WAN/DHCP. Now if I connect a PC to any of the remaining ports, I can't get an IP from the Netgear's DHCP server. What am I doing wrong?

int fastEthernet1/0/1
    switchport access vlan 10
    description NETGEAR

int fastEthernet1/0/2
    switchport access vlan 10
    description ConnectedToPC

int fastEthernet1/0/3
    switchport access vlan 10

int fastEthernet1/0/4
    switchport access vlan 10

int fastEthernet1/0/5
    switchport access vlan 10

int fastEthernet1/0/6
    switchport access vlan 10

 If I connect a PC to port 2 and another to port 3; and give them an IP in the same subnet, I can ping them. But the DHCP is the issue.

[marce1000]

 - Should work at first glance, is there anything in the logs (of the switch and or the DHCP server) ; when you force the PC to get a new IP with (ipconfig /release and renew) for instance. It's best to test this explicit in order to not confuse with machines having an IP already.

 M.

[chrihussey]

Hello, 

Try adding "spanning-tree portfast" to the access ports. Without it DHCP requests don't get forwarded while spanning tree is being negotiated when the ports come up.

Hope this helps

[Frank Sinatra]

I added spanning tree to both ports but it's still the same. There is a trunk on the switch. Could it be causing any issues?

[paul driver]

Hello

First of all you may require a crossover cable between the the switch and the negear router/siwtch if the ports are not mdix compatible.

Second put all access ports on the new switch in access vlan 1 test again

switch
interface x/x
switchport host
switchport access vlan 1

[romanroma]

You might need DHCP snoop turned on. The multicast/broadcast for DHCP discovery might be not getting to the server.