@@ -12,6 +12,10 @@ var (

 	ErrNetworkOverlaps                = errors.New("requested network overlaps with existing network")

 )

+var (

+	networkGetRoutesFct = netlink.NetworkGetRoutes

+)

+

 func CheckNameserverOverlaps(nameservers []string, toCheck *net.IPNet) error {

 	if len(nameservers) > 0 {

 		for _, ns := range nameservers {

@@ -28,7 +32,7 @@ func CheckNameserverOverlaps(nameservers []string, toCheck *net.IPNet) error {

 }

 func CheckRouteOverlaps(toCheck *net.IPNet) error {

-	networks, err := netlink.NetworkGetRoutes()

+	networks, err := networkGetRoutesFct()

 	if err != nil {

 		return err

 	}

@@ -35,12 +35,19 @@ func TestOverlapingNameservers(t *testing.T) {

 }

 func TestCheckRouteOverlaps(t *testing.T) {

-	routesData := []string{"10.0.2.0/32", "10.0.3.0/24", "10.0.42.0/24", "172.16.42.0/24", "192.168.142.0/24"}

-

-	routes := []netlink.Route{}

-	for _, addr := range routesData {

-		_, netX, _ := net.ParseCIDR(addr)

-		routes = append(routes, netlink.Route{IPNet: netX})

+	orig := networkGetRoutesFct

+	defer func() {

+		networkGetRoutesFct = orig

+	}()

+	networkGetRoutesFct = func() ([]netlink.Route, error) {

+		routesData := []string{"10.0.2.0/32", "10.0.3.0/24", "10.0.42.0/24", "172.16.42.0/24", "192.168.142.0/24"}

+

+		routes := []netlink.Route{}

+		for _, addr := range routesData {

+			_, netX, _ := net.ParseCIDR(addr)

+			routes = append(routes, netlink.Route{IPNet: netX})

+		}

+		return routes, nil

 	}

 	_, netX, _ := net.ParseCIDR("172.16.0.1/24")