Last night I changed the IP address of my dhcp server which resides on a Windows server. I forgot to change the ip-helper entry for the vlan interfaces on our switch, so that broke dhcp. This morning I went in and removed the old ip-helper address entry and entered the new one. I thought that would take care of it but the requests aren't getting through. I can see by my dhcp logs that the dhcp server is not getting the requests. Is there something I have to do to clear/refresh so that the new ip-helper address entry works?