diff --git a/go.mod b/go.mod
index 1fb2480..e8bbf76 100644
--- a/go.mod
+++ b/go.mod
@@ -15,6 +15,7 @@ require (
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.62.0 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/yl2chen/cidranger v1.0.2 // indirect
 	golang.org/x/sys v0.30.0 // indirect
 	google.golang.org/protobuf v1.36.5 // indirect
 )
diff --git a/go.sum b/go.sum
index f602bc3..62d4f44 100644
--- a/go.sum
+++ b/go.sum
@@ -6,6 +6,7 @@ github.com/bsm/gomega v1.27.10 h1:yeMWxP2pV2fG3FgAODIY8EiRE3dy0aeFYt4l7wh6yKA=
 github.com/bsm/gomega v1.27.10/go.mod h1:JyEr/xRbxbtgWNi8tIEVPUYZ5Dzef52k01W3YH0H+O0=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
@@ -30,11 +31,17 @@ github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0leargg
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/redis/go-redis/v9 v9.10.0 h1:FxwK3eV8p/CQa0Ch276C7u2d0eNC9kCmAYQ7mCXCzVs=
 github.com/redis/go-redis/v9 v9.10.0/go.mod h1:huWgSWd8mW6+m0VPhJjSSQ+d6Nh1VICQ6Q5lHuCH/Iw=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/yl2chen/cidranger v1.0.2 h1:lbOWZVCG1tCRX4u24kuM1Tb4nHqWkDxwLdoS+SevawU=
+github.com/yl2chen/cidranger v1.0.2/go.mod h1:9U1yz7WPYDwf0vpNWFaeRh0bjwz5RVgRy/9UEQfHl0g=
 golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
 golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 google.golang.org/protobuf v1.36.5 h1:tPhr+woSbjfYvY6/GPufUoYizxw1cF/yFoxJ2fmpwlM=
 google.golang.org/protobuf v1.36.5/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/main.go b/main.go
index 8356409..e98c1c9 100644
--- a/main.go
+++ b/main.go
@@ -19,8 +19,61 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/redis/go-redis/v9"
+	"github.com/yl2chen/cidranger"
 )
 
+// ──────────────────────────────────────────────
+// Ranger-Cache (statt prefixCache)
+// ──────────────────────────────────────────────
+type rangerCacheEntry struct {
+	ranger   cidranger.Ranger
+	expireAt time.Time
+}
+
+var (
+	rangerCache   = map[string]rangerCacheEntry{}
+	rangerCacheMu sync.RWMutex
+)
+
+// buildCategoryRanger holt alle CIDRs aus Redis, baut einen PCTrie
+// und legt ihn 10 Minuten im Cache ab.
+func buildCategoryRanger(cat string) (cidranger.Ranger, error) {
+	rangerCacheMu.Lock()
+	// Cache-Hit?
+	if e, ok := rangerCache[cat]; ok && time.Now().Before(e.expireAt) {
+		rangerCacheMu.Unlock()
+		return e.ranger, nil
+	}
+	rangerCacheMu.Unlock()
+
+	// Redis auslesen
+	keys, err := rdb.HKeys(ctx, "bl:"+cat).Result()
+	if err != nil {
+		return nil, err
+	}
+
+	r := cidranger.NewPCTrieRanger()
+	for _, k := range keys {
+		k = strings.TrimSpace(k)
+		_, ipNet, err := net.ParseCIDR(k)
+		if err != nil {
+			fmt.Printf("⚠️ Ungültiger Redis-Prefix %s: %s\n", cat, k)
+			continue
+		}
+		_ = r.Insert(cidranger.NewBasicRangerEntry(*ipNet))
+	}
+
+	// Cache aktualisieren
+	rangerCacheMu.Lock()
+	rangerCache[cat] = rangerCacheEntry{
+		ranger:   r,
+		expireAt: time.Now().Add(10 * time.Minute),
+	}
+	rangerCacheMu.Unlock()
+
+	return r, nil
+}
+
 // Redis + Context
 var ctx = context.Background()
 var rdb = redis.NewClient(&redis.Options{
@@ -61,17 +114,6 @@ var blocklistURLs = map[string]string{
 	"bitwire": "https://raw.githubusercontent.com/bitwire-it/ipblocklist/refs/heads/main/ip-list.txt",
 }
 
-// Präfix-Cache
-type prefixCacheEntry struct {
-	prefixes []netip.Prefix
-	expireAt time.Time
-}
-
-var (
-	prefixCache   = map[string]prefixCacheEntry{}
-	prefixCacheMu sync.RWMutex
-)
-
 // Prometheus Metriken
 var (
 	checkRequests = prometheus.NewCounter(prometheus.CounterOpts{
@@ -311,10 +353,6 @@ func handleWhitelist(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "redis error", http.StatusInternalServerError)
 		return
 	}
-
-	// Optional: Cache leeren für die IP
-	prefixCacheMu.Lock()
-	defer prefixCacheMu.Unlock()
 	// Kein spezifischer IP-Cache in deinem Design, aber hier könnte man Cache invalidieren falls nötig
 
 	writeJSON(w, map[string]string{
@@ -334,7 +372,7 @@ func handleCheck(w http.ResponseWriter, r *http.Request) {
 	}
 
 	var cats []string
-	for a, _ := range blocklistURLs {
+	for a := range blocklistURLs {
 		cats = append(cats, a)
 	}
 
@@ -366,6 +404,12 @@ func handleTraefik(w http.ResponseWriter, r *http.Request) {
 	if ipStr == "" {
 		ipStr = r.RemoteAddr
 	}
+	ipStr = strings.TrimSpace(strings.Split(ipStr, ",")[0]) // evtl. mehrere IPs
+
+	// Port abschneiden – funktioniert für IPv4 und IPv6:
+	if host, _, err := net.SplitHostPort(ipStr); err == nil {
+		ipStr = host
+	}
 	ip, err := netip.ParseAddr(ipStr)
 	if err != nil {
 		http.Error(w, "invalid IP", http.StatusBadRequest)
@@ -373,7 +417,7 @@ func handleTraefik(w http.ResponseWriter, r *http.Request) {
 	}
 
 	var cats []string
-	for a, _ := range blocklistURLs {
+	for a := range blocklistURLs {
 		cats = append(cats, a)
 	}
 
@@ -400,59 +444,28 @@ func handleTraefik(w http.ResponseWriter, r *http.Request) {
 
 // Check-Logik
 func checkIP(ip netip.Addr, cats []string) ([]string, error) {
-	wl, err := rdb.Exists(ctx, "wl:"+ip.String()).Result()
-	if err != nil {
-		return nil, err
+	// Whitelist zuerst prüfen
+	if wl, err := rdb.Exists(ctx, "wl:"+ip.String()).Result(); err == nil && wl > 0 {
+		return nil, nil
 	}
-	if wl > 0 {
-		return []string{}, nil
-	}
-	matches := []string{}
+
+	var matches []string
+	needle := net.IP(ip.AsSlice())
+
 	for _, cat := range cats {
-		prefixes, err := loadCategoryPrefixes(cat)
+		r, err := buildCategoryRanger(cat)
 		if err != nil {
 			return nil, err
 		}
-		for _, pfx := range prefixes {
-			if pfx.Contains(ip) {
-				fmt.Printf("💡 MATCH: %s in %s (%s)\n", ip, cat, pfx)
-				matches = append(matches, cat)
-				break
-			}
+		ok, _ := r.Contains(needle)
+		if ok {
+			fmt.Printf("💡 MATCH: %s in %s\n", ip, cat)
+			matches = append(matches, cat)
 		}
 	}
 	return matches, nil
 }
 
-func loadCategoryPrefixes(cat string) ([]netip.Prefix, error) {
-	prefixCacheMu.Lock()
-	defer prefixCacheMu.Unlock()
-	entry, ok := prefixCache[cat]
-	if ok && time.Now().Before(entry.expireAt) {
-		return entry.prefixes, nil
-	}
-	keys, err := rdb.HKeys(ctx, "bl:"+cat).Result()
-	if err != nil {
-		return nil, err
-	}
-	var prefixes []netip.Prefix
-	for _, k := range keys {
-		k = strings.TrimSpace(k)
-		pfx, err := netip.ParsePrefix(k)
-		if err == nil {
-			prefixes = append(prefixes, pfx)
-		} else {
-			fmt.Printf("⚠️ Ungültiger Redis-Prefix %s: %s\n", cat, k)
-		}
-	}
-	prefixCache[cat] = prefixCacheEntry{
-		prefixes: prefixes,
-		expireAt: time.Now().Add(10 * time.Minute),
-		//Hier geändert von 1 * time.Second
-	}
-	return prefixes, nil
-}
-
 // JSON-Helfer
 func writeJSON(w http.ResponseWriter, v any) {
 	w.Header().Set("Content-Type", "application/json")