def getRouterInstanceByPortAndProtocol(self, protocol, vport):
        """
        Description
            Get router instance for the specified protocol on a speficied vport

        Parameters
            protocol: <str>: protocol to get a router instance
            vport: <str>: vport instance eg: "/api/v1/sessions/1/ixnetwork/vport/1"

        Syntax
            GET: /api/v1/sessions/{id}/ixnetwork/vport/{id}/protocols/<protocol>/router
            GET: /api/v1/sessions/{id}/ixnetwork/vport/{id}/protocols/<protocol>/neighborRange
            GET: /api/v1/sessions/{id}/ixnetwork/vport/{id}/protocols/<protocol>/host
            GET: /api/v1/sessions/{id}/ixnetwork/vport/{id}/protocols/<protocol>/bridge
            GET: /api/v1/sessions/{id}/ixnetwork/vport/{id}/protocols/<protocol>/actor
            GET: /api/v1/sessions/{id}/ixnetwork/vport/{id}/protocols/<protocol>/neighborPair

        Examples
            getRouterInstanceByPortAndProtocol(protocol='ospf', vport='/api/v1/sessions/1/ixnetwork/vport/1')

        Return
            RouterInstanceList
            Returns [] if no router instance exists
        """
        if protocol == 'bgp':
            nextNode = '/neighborRange'
        elif protocol == 'igmp' or protocol == 'mld':
            nextNode = '/host'
        elif protocol == 'stp':
            nextNode = '/bridge'
        elif protocol == 'rsvp':
            nextNode = '/neighborPair'
        elif protocol == 'lacp':
            nextNode = '/link'
        else:
            nextNode = '/router'
        url = vport+'/protocols/'+protocol+nextNode
        response = self.ixnObj.get(url)
        RouterInstanceList = ["%s" % (str(i["links"][0]["href"])) for i in response.json()]
        self.ixnObj.logInfo('Router Instance list %s' % RouterInstanceList)
        return RouterInstanceList