DHCP failed, APIPA being used when trying to give PC's an IP address.

[conor5]

My DHCP server1 is configured to ignore the first 10 addresses, which I did using 'ip dhcp excluded-address 192.168.20.2 192.168.20.11' in the cli of the router.

I gave it an ip address, a subnet mask and and a default gateway which i kept out of the excluded addresses and configured the dhcp server to have a start ip address of 192.169.20.11.

I am unsure as to what I am doing wrong for the DHCP to fail.

[conor5]

I have discovered that the DHCP server works when connected directly to one PC, however when attached to a router and a switch, the error occurs.