diff --git a/component/routing/domain_matcher/ahocorasick_slimtrie.go b/component/routing/domain_matcher/ahocorasick_slimtrie.go
index 3a5349c..38cfb2f 100644
--- a/component/routing/domain_matcher/ahocorasick_slimtrie.go
+++ b/component/routing/domain_matcher/ahocorasick_slimtrie.go
@@ -100,11 +100,12 @@ func (n *AhocorasickSlimtrie) MatchDomainBitmap(domain string) (bitmap []uint32)
 	bitmap = make([]uint32, N)
 	domain = strings.ToLower(strings.TrimSuffix(domain, "."))
 	// Domain should consist of 'a'-'z' and '.' and '-'
-	for _, b := range []byte(domain) {
-		if !ahocorasick.IsValidChar(b) {
-			return bitmap
-		}
-	}
+	// NOTE: DO NOT VERIFY THE DOMAIN TO MATCH: https://github.com/daeuniverse/dae/issues/528
+	// for _, b := range []byte(domain) {
+	// 	if !ahocorasick.IsValidChar(b) {
+	// 		return bitmap
+	// 	}
+	// }
 	// Suffix matching.
 	suffixTrieDomain := ToSuffixTrieString("^" + domain)
 	for _, i := range n.validTrieIndexes {
diff --git a/component/routing/domain_matcher/ahocorasick_slimtrie_test.go b/component/routing/domain_matcher/ahocorasick_slimtrie_test.go
index 49017db..4ee8731 100644
--- a/component/routing/domain_matcher/ahocorasick_slimtrie_test.go
+++ b/component/routing/domain_matcher/ahocorasick_slimtrie_test.go
@@ -6,11 +6,12 @@
 package domain_matcher
 
 import (
+	"math/rand"
+	"testing"
+
 	"github.com/daeuniverse/dae/common/consts"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/exp/slices"
-	"math/rand"
-	"testing"
 )
 
 func TestAhocorasickSlimtrie(t *testing.T) {
diff --git a/component/sniffing/http.go b/component/sniffing/http.go
index 10ef494..e3cb440 100644
--- a/component/sniffing/http.go
+++ b/component/sniffing/http.go
@@ -60,7 +60,7 @@ func (s *Sniffer) SniffHttp() (d string, err error) {
 			continue
 		}
 		if strings.EqualFold(string(key), "host") {
-			return strings.TrimSpace(string(value)), nil
+			return string(value), nil
 		}
 	}
 	return "", ErrNotFound
diff --git a/component/sniffing/sniffer.go b/component/sniffing/sniffer.go
index 8e4813a..301e11d 100644
--- a/component/sniffing/sniffer.go
+++ b/component/sniffing/sniffer.go
@@ -75,7 +75,7 @@ func sniffGroup(sniffs ...sniff) (d string, err error) {
 	for _, sniffer := range sniffs {
 		d, err = sniffer()
 		if err == nil {
-			return d, nil
+			return NormalizeDomain(d), nil
 		}
 		if err != ErrNotApplicable {
 			return "", err
diff --git a/component/sniffing/sniffing.go b/component/sniffing/sniffing.go
index 937707c..acd59bd 100644
--- a/component/sniffing/sniffing.go
+++ b/component/sniffing/sniffing.go
@@ -8,6 +8,8 @@ package sniffing
 import (
 	"errors"
 	"fmt"
+	"net"
+	"strings"
 )
 
 var (
@@ -19,3 +21,15 @@ var (
 func IsSniffingError(err error) bool {
 	return errors.Is(err, Error)
 }
+
+func NormalizeDomain(host string) string {
+	host = strings.ToLower(strings.TrimSpace(host))
+	if strings.HasSuffix(host, "]") {
+		// Sniffed domain may be like `[2606:4700:20::681a:d1f]`. We should remove the brackets.
+		return strings.Trim(host, "[]")
+	}
+	if domain, _, err := net.SplitHostPort(host); err == nil {
+		return domain
+	}
+	return strings.TrimSuffix(host, ".")
+}