add dhcp failing test

examples/stackbasic/main.go

@@ -36,7 +36,7 @@ func main() {
 	ip := netip.MustParseAddr(stackIP)
 	tap := ltesto.NewHTTPTapClient("http://127.0.0.1:7070")
 
-	ippfx := tap.IPPrefix()
+	ippfx, _ := tap.IPMask()
 	if !ippfx.Contains(ip) {
 		log.Fatal("interface does not contain stack address")
 	}
@@ -46,8 +46,8 @@ func main() {
 	}))
 
 	slogger := logger{lg}
-	gatewayMAC := tap.HardwareAddr6()
-	mtu := tap.MTU()
+	gatewayMAC, _ := tap.HardwareAddress6()
+	mtu, _ := tap.MTU()
 	lStack, handler, err := NewEthernetTCPStack(stackHWAddr, gatewayMAC, addrPort, uint16(mtu), slogger)
 	if err != nil {
 		log.Fatal(err)