diff --git a/device.go b/device.go
index 64bf431..f9f6707 100644
--- a/device.go
+++ b/device.go
@@ -193,7 +193,7 @@ func (nc *NetCard) runRead() {
 				rframe = rframe[:n]
 			})
 
-			if waterutil.IsIPv4(rframe) || waterutil.IPv4Source(rframe).Equal(net.IPv4(0, 0, 0, 0)) {
+			if !waterutil.IsIPv4(rframe) || waterutil.IPv4Source(rframe).Equal(net.IPv4(0, 0, 0, 0)) {
 				continue
 			}