This paper proposes an auto-configuration mechanism for a newly attached SDN (Software-defined Networking) switch and intermediate switches in an SDN/non-SDN hybrid network. Automation of initial configuration of SDN switches brings the benefit of reducing the installation costs and maintaining the operational consistency in an enterprise network. However, the heterogeneity of a hybrid network introduces difficulty in achieving such benefits. The proposed system achieves the following features: 1) detecting a new SDN switch in a hybrid network, 2) providing the switch with appropriate configuration parameters in an SDN/non-SDN hybrid network and 3) ensuring seamless service across the SDN and non-SDN segments. The proposed solution also introduces DHCP-SDN as an extension of Dynamic Host Configuration Protocol (DHCP) to support SDN parameters. The proposed system enables a new SDN switch to automatically start operating even though the intermediate switches are not configured with the SDN-specific VLAN setup. © 2015 ACM.