A method comprising: creating, by a Software Defined Network ,SDN, controller of a network system, a service chain comprising a plurality of Physical Network Functions ,PNFs, including a first PNF and a second PNF , the service chain between a first logical router and a second logical router of the network system; creating, for each of the first PNF and the second PNF, a corresponding first routing instance and a corresponding second routing instance ; configuring, for each of the first PNF and the second PNF, the corresponding first routing instance with a first label comprising a first Virtual eXtensible Local Area Network VXLAN, Identifier ,VNID, of a first virtual network associated with the first logical router and the second routing instance with a second label comprising a second VNID of a second virtual network associated with the second logical router; creating a first route between a first device on the first virtual network towards a second device on the second virtual network through the service chain, the first route specifying, in a first switch between the first device and the first PNF, the first VNID of the first routing instance of the first PNF as a first label for a next hop from the first switch to the first PNF, and specifying, in a second switch between the first PNF and the second PNF, the first VNID of the first routing instance of the second PNF as a second label for a next hop from the second switch to the second PNF; and pushing the first route to at least one of a plurality of switches communicatively coupled to one or more of the plurality of PNFs, the plurality of switches including the first switch and the second switch. creating, by a Software Defined Network ,SDN, controller of a network system, a service chain comprising a plurality of Physical Network Functions ,PNFs, including a first PNF and a second PNF , the service chain between a first logical router and a second logical router of the network system; creating, for each of the first PNF and the second PNF, a corresponding first routing instance and a corresponding second routing instance ; configuring, for each of the first PNF and the second PNF, the corresponding first routing instance with a first label comprising a first Virtual eXtensible Local Area Network VXLAN, Identifier ,VNID, of a first virtual network associated with the first logical router and the second routing instance with a second label comprising a second VNID of a second virtual network associated with the second logical router; creating a first route between a first device on the first virtual network towards a second device on the second virtual network through the service chain, the first route specifying, in a first switch between the first device and the first PNF, the first VNID of the first routing instance of the first PNF as a first label for a next hop from the first switch to the first PNF, and specifying, in a second switch between the first PNF and the second PNF, the first VNID of the first routing instance of the second PNF as a second label for a next hop from the second switch to the second PNF; and pushing the first route to at least one of a plurality of switches communicatively coupled to one or more of the plurality of PNFs, the plurality of switches including the first switch and the second switch. <EOS>