diff --git a/net/netns/netns_darwin.go b/net/netns/netns_darwin.go
index 55e29cc29..ac5e89d76 100644
--- a/net/netns/netns_darwin.go
+++ b/net/netns/netns_darwin.go
@@ -92,7 +92,9 @@ func getInterfaceIndex(logf logger.Logf, netMon *netmon.Monitor, address string)
 	// If the address doesn't parse, use the default index.
 	addr, err := parseAddress(address)
 	if err != nil {
-		logf("[unexpected] netns: error parsing address %q: %v", address, err)
+		if err != errUnspecifiedHost {
+			logf("[unexpected] netns: error parsing address %q: %v", address, err)
+		}
 		return defaultIdx()
 	}
 
diff --git a/net/netns/netns_dw.go b/net/netns/netns_dw.go
index bf654666f..f92ba9462 100644
--- a/net/netns/netns_dw.go
+++ b/net/netns/netns_dw.go
@@ -6,16 +6,22 @@
 package netns
 
 import (
+	"errors"
 	"net"
 	"net/netip"
 )
 
+var errUnspecifiedHost = errors.New("unspecified host")
+
 func parseAddress(address string) (addr netip.Addr, err error) {
 	host, _, err := net.SplitHostPort(address)
 	if err != nil {
 		// error means the string didn't contain a port number, so use the string directly
 		host = address
 	}
+	if host == "" {
+		return addr, errUnspecifiedHost
+	}
 
 	return netip.ParseAddr(host)
 }
diff --git a/net/netns/netns_windows.go b/net/netns/netns_windows.go
index c78001560..afbda0f47 100644
--- a/net/netns/netns_windows.go
+++ b/net/netns/netns_windows.go
@@ -102,7 +102,9 @@ func controlC(logf logger.Logf, network, address string, c syscall.RawConn) (err
 				}
 			}
 		} else {
-			logf("[unexpected] netns: error parsing address %q: %v", address, err)
+			if err != errUnspecifiedHost {
+				logf("[unexpected] netns: error parsing address %q: %v", address, err)
+			}
 			ifaceIdxV4, ifaceIdxV6 = defIfaceIdxV4, defIfaceIdxV6
 		}
 	} else {