diff --git a/group/group.go b/group/group.go
index 4782443..d30fb61 100644
--- a/group/group.go
+++ b/group/group.go
@@ -23,9 +23,8 @@ type Group struct {
 	ipsetToLink *netfilterHelper.IPSetToLink
 }
 
-func (g *Group) AddIP(address net.IP, ttl time.Duration) error {
-	ttlSeconds := uint32(ttl.Seconds())
-	return g.ipset.AddIP(address, &ttlSeconds)
+func (g *Group) AddIP(address net.IP, ttl uint32) error {
+	return g.ipset.AddIP(address, &ttl)
 }
 
 func (g *Group) DelIP(address net.IP) error {
@@ -90,7 +89,7 @@ func (g *Group) Disable() []error {
 func (g *Group) Sync(records *records.Records) error {
 	now := time.Now()
 
-	addresses := make(map[string]time.Duration)
+	addresses := make(map[string]uint32)
 	knownDomains := records.ListKnownDomains()
 	for _, domain := range g.Rules {
 		if !domain.IsEnabled() {
@@ -104,7 +103,7 @@ func (g *Group) Sync(records *records.Records) error {
 
 			domainAddresses := records.GetARecords(domainName)
 			for _, address := range domainAddresses {
-				ttl := now.Sub(address.Deadline)
+				ttl := uint32(now.Sub(address.Deadline).Seconds())
 				if oldTTL, ok := addresses[string(address.Address)]; !ok || ttl > oldTTL {
 					addresses[string(address.Address)] = ttl
 				}
diff --git a/kvas2.go b/kvas2.go
index 0e2279d..291fbf4 100644
--- a/kvas2.go
+++ b/kvas2.go
@@ -29,11 +29,12 @@ var (
 )
 
 type Config struct {
-	MinimalTTL             time.Duration
+	AdditionalTTL          uint32
 	ChainPrefix            string
 	IpSetPrefix            string
 	LinkName               string
 	TargetDNSServerAddress string
+	TargetDNSServerPort    uint16
 	ListenDNSPort          uint16
 }
 
@@ -316,10 +317,7 @@ func (a *App) processARecord(aRecord dns.A) {
 		Int("ttl", int(aRecord.Hdr.Ttl)).
 		Msg("processing a record")
 
-	ttlDuration := time.Duration(aRecord.Hdr.Ttl) * time.Second
-	if ttlDuration < a.Config.MinimalTTL {
-		ttlDuration = a.Config.MinimalTTL
-	}
+	ttlDuration := aRecord.Hdr.Ttl + a.Config.AdditionalTTL
 
 	a.Records.AddARecord(aRecord.Hdr.Name[:len(aRecord.Hdr.Name)-1], aRecord.A, ttlDuration)
 
@@ -362,10 +360,7 @@ func (a *App) processCNameRecord(cNameRecord dns.CNAME) {
 		Int("ttl", int(cNameRecord.Hdr.Ttl)).
 		Msg("processing cname record")
 
-	ttlDuration := time.Duration(cNameRecord.Hdr.Ttl) * time.Second
-	if ttlDuration < a.Config.MinimalTTL {
-		ttlDuration = a.Config.MinimalTTL
-	}
+	ttlDuration := cNameRecord.Hdr.Ttl + a.Config.AdditionalTTL
 
 	a.Records.AddCNameRecord(cNameRecord.Hdr.Name[:len(cNameRecord.Hdr.Name)-1], cNameRecord.Target, ttlDuration)
 
@@ -384,7 +379,7 @@ func (a *App) processCNameRecord(cNameRecord dns.CNAME) {
 					continue
 				}
 				for _, aRecord := range aRecords {
-					err := group.AddIP(aRecord.Address, now.Sub(aRecord.Deadline))
+					err := group.AddIP(aRecord.Address, uint32(now.Sub(aRecord.Deadline).Seconds()))
 					if err != nil {
 						log.Error().
 							Str("address", aRecord.Address.String()).
@@ -429,7 +424,7 @@ func New(config Config) (*App, error) {
 
 	app.DNSMITM = dnsMitmProxy.New()
 	app.DNSMITM.TargetDNSServerAddress = app.Config.TargetDNSServerAddress
-	app.DNSMITM.TargetDNSServerPort = 53
+	app.DNSMITM.TargetDNSServerPort = app.Config.TargetDNSServerPort
 	app.DNSMITM.RequestHook = func(clientAddr net.Addr, reqMsg dns.Msg, network string) (*dns.Msg, *dns.Msg, error) {
 		// TODO: Need to understand why it not works in proxy mode
 		if len(reqMsg.Question) == 1 && reqMsg.Question[0].Qtype == dns.TypePTR {
diff --git a/main.go b/main.go
index 8c3ff35..6122999 100644
--- a/main.go
+++ b/main.go
@@ -2,12 +2,11 @@ package main
 
 import (
 	"context"
-	"github.com/rs/zerolog"
 	"os"
 	"os/signal"
 	"syscall"
-	"time"
 
+	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
 )
 
@@ -15,12 +14,13 @@ func main() {
 	log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr})
 
 	app, err := New(Config{
-		MinimalTTL:             time.Hour,
+		AdditionalTTL:          216000, // 1 hour
 		ChainPrefix:            "KVAS2_",
 		IpSetPrefix:            "kvas2_",
 		LinkName:               "br0",
 		TargetDNSServerAddress: "127.0.0.1",
-		ListenDNSPort:          7553,
+		TargetDNSServerPort:    53,
+		ListenDNSPort:          3553,
 	})
 	if err != nil {
 		log.Fatal().Err(err).Msg("failed to initialize application")
diff --git a/records/records.go b/records/records.go
index 7c6ad97..6f9ac63 100644
--- a/records/records.go
+++ b/records/records.go
@@ -22,7 +22,7 @@ type Records struct {
 	records map[string]interface{}
 }
 
-func (r *Records) AddCNameRecord(domainName, alias string, ttl time.Duration) {
+func (r *Records) AddCNameRecord(domainName, alias string, ttl uint32) {
 	if domainName == alias {
 		return
 	}
@@ -30,16 +30,16 @@ func (r *Records) AddCNameRecord(domainName, alias string, ttl time.Duration) {
 	r.mux.Lock()
 	r.records[domainName] = &CNameRecord{
 		Alias:    alias,
-		Deadline: time.Now().Add(ttl),
+		Deadline: time.Now().Add(time.Duration(ttl) * time.Second),
 	}
 	r.mux.Unlock()
 }
 
-func (r *Records) AddARecord(domainName string, addr net.IP, ttl time.Duration) {
+func (r *Records) AddARecord(domainName string, addr net.IP, ttl uint32) {
 	r.mux.Lock()
 	defer r.mux.Unlock()
 
-	deadline := time.Now().Add(ttl)
+	deadline := time.Now().Add(time.Duration(ttl) * time.Second)
 
 	aRecords, _ := r.records[domainName].([]*ARecord)
 	for _, aRecord := range aRecords {