The present invention provides a method for enabling Segment Routing in a multi-domain network comprising a client network domain and a server network domain, where the client network domain is a packet network domain and the server network domain is a connected-oriented network domain. The method comprises assigning a network segment identifier to each of one or more potential paths through the server network domain between a pair of overlay network nodes in the client network domain, wherein the one or more potential paths are not pre-configured and the or each network segment identifier is suitable for inclusion in one or more data packets to indicate to at least one of the pair of overlay network nodes a preselected network segment routing for the one or more data packets. The present invention further provides a method for routing data packets in the multi-domain network. The method, in an overlay network node in the client network domain, comprises receiving one or more data packets, and retrieving a network segment identifier included in at least one of the one or more data packets. The method further comprises determining that the network segment identifier indicates that the one or more data packets should be routed over a pre-selected potential path through the server network domain, and, based on the determining, triggering the server network domain to configure the pre-selected potential path through the server network domain.