net: change cname lookup test target to iana.org

It might be meaningful, and stable than others.

R=golang-dev, agl
CC=golang-dev
https://golang.org/cl/6499091

src/pkg/net/dialgoogle_test.go

@@ -41,17 +41,6 @@ func doDial(t *testing.T, network, addr string) {
 	fd.Close()
 }
 
-func TestLookupCNAME(t *testing.T) {
-	if testing.Short() || !*testExternal {
-		t.Logf("skipping test to avoid external network")
-		return
-	}
-	cname, err := LookupCNAME("www.google.com")
-	if !strings.HasSuffix(cname, ".l.google.com.") || err != nil {
-		t.Errorf(`LookupCNAME("www.google.com.") = %q, %v, want "*.l.google.com.", nil`, cname, err)
-	}
-}
-
 var googleaddrsipv4 = []string{
 	"%d.%d.%d.%d:80",
 	"www.google.com:80",

src/pkg/net/lookup_test.go

@@ -9,6 +9,7 @@ package net
 
 import (
 	"flag"
+	"strings"
 	"testing"
 )
 
@@ -79,6 +80,17 @@ func TestGoogleDNSAddr(t *testing.T) {
 	}
 }
 
+func TestLookupIANACNAME(t *testing.T) {
+	if testing.Short() || !*testExternal {
+		t.Logf("skipping test to avoid external network")
+		return
+	}
+	cname, err := LookupCNAME("www.iana.org")
+	if !strings.HasSuffix(cname, ".icann.org.") || err != nil {
+		t.Errorf(`LookupCNAME("www.iana.org.") = %q, %v, want "*.icann.org.", nil`, cname, err)
+	}
+}
+
 var revAddrTests = []struct {
 	Addr      string
 	Reverse   string