diff --git a/src/main/java/component/CanBePrefix.java b/src/main/java/component/CanBePrefix.java
index 2ec6393..8cdae09 100644
--- a/src/main/java/component/CanBePrefix.java
+++ b/src/main/java/component/CanBePrefix.java
@@ -16,6 +16,7 @@ public class CanBePrefix implements TlvComponentBase,InitialAble, IEncodingAble
     // 函数
     public void setCanBePrefix(boolean canBePrefix){
         this.canBePrefix=canBePrefix;
+        this.doInitial();
     }
 
     public boolean getCanBePrefix(){
diff --git a/src/main/java/component/CongestionMark.java b/src/main/java/component/CongestionMark.java
index 2560215..f2d044b 100644
--- a/src/main/java/component/CongestionMark.java
+++ b/src/main/java/component/CongestionMark.java
@@ -82,9 +82,9 @@ public class CongestionMark implements TlvComponentBase,InitialAble, IEncodingAb
             return false;
         }
 
-        // 读取 interestLifeTime
+        // 读取 CongestionMark
         long value=TLV.readNonNegativeInteger(block.getValue(),0,block.getLength().getVlIntValue2Int());
-        if(value==0){
+        if(value<0){
             return false;
         }
         this.setCongestionLevel(value);
diff --git a/src/main/java/component/FreshnessPeriod.java b/src/main/java/component/FreshnessPeriod.java
index a42beb3..4156b86 100644
--- a/src/main/java/component/FreshnessPeriod.java
+++ b/src/main/java/component/FreshnessPeriod.java
@@ -20,6 +20,7 @@ public class FreshnessPeriod implements TlvComponentBase,InitialAble, IEncodingA
 
     public void setFreshnessPeriod(long freshnessPeriod) {
         this.freshnessPeriod = freshnessPeriod;
+        this.doInitial();
     }
 
     // 接口实现-变量区
@@ -83,7 +84,7 @@ public class FreshnessPeriod implements TlvComponentBase,InitialAble, IEncodingA
 
         // 读取 FreshnessPeriod
         long value=TLV.readNonNegativeInteger(block.getValue(),0,block.getLength().getVlIntValue2Int());
-        if(value==0){
+        if(value<0){
             return false;
         }
         this.setFreshnessPeriod(value);
diff --git a/src/main/java/component/HopLimit.java b/src/main/java/component/HopLimit.java
new file mode 100644
index 0000000..6c26e96
--- /dev/null
+++ b/src/main/java/component/HopLimit.java
@@ -0,0 +1,89 @@
+package component;
+
+import encoding.*;
+
+/*
+ * @Author: Wang Feng
+ * @Description:
+ * @Version: 1.0.0
+ * @Date: 16:38 2021/3/9
+ * @Copyright: MIN-Group；国家重大科技基础设施——未来网络北大实验室；深圳市信息论与未来网络重点实验室
+ */
+public class HopLimit implements TlvComponentBase,InitialAble, IEncodingAble {
+    // 成员变量
+    private long hopLimit;
+
+    // 成员函数
+    public long getHopLimit() {
+        return hopLimit;
+    }
+
+    public void setHopLimit(long hopLimit) {
+        this.hopLimit = hopLimit;
+        this.doInitial();
+    }
+
+    // 接口实现-变量区
+    private boolean initial=false;
+
+    // 接口实现-方法区
+    @Override
+    public void doInitial() {
+        initial=true;
+    }
+
+    @Override
+    public boolean isInitial() {
+        return initial;
+    }
+
+    /**
+     *
+     * @param encoder
+     * @return
+     */
+    @Override
+    public int wireEncode(Encoder encoder) {
+        int totalLength=0;
+
+        // 编码 TLV-VALUE
+        int tmplen=encoder.prependNonNegativeInteger(this.hopLimit);
+        if(tmplen==0){
+            return 0;
+        }
+        totalLength+=tmplen;
+
+        // 编码 TLV-LENGTH
+        tmplen+=encoder.prependVarNumber(new VlInt(totalLength));
+        if(tmplen==0){
+            return 0;
+        }
+        totalLength+=tmplen;
+
+        // 编码 TLV-TYPE
+        tmplen+=encoder.prependVarNumber(new VlInt(TLV.TlvHopLimit));
+        if(tmplen==0){
+            return 0;
+        }
+        totalLength+=tmplen;
+
+        return totalLength;
+    }
+
+    @Override
+    public boolean wireDecode(Block block) {
+        // 检查 Type 是否正确
+        if(!TLV.expectType(block.getTlvType(),new VlInt(TLV.TlvHopLimit))){
+            return false;
+        }
+
+        // 读取 HopLimit
+        long value=TLV.readNonNegativeInteger(block.getValue(),0,block.getLength().getVlIntValue2Int());
+        if(value<0){
+            return false;
+        }
+        this.setHopLimit(value);
+
+        return true;
+    }
+}
diff --git a/src/main/java/component/MustBeRefresh.java b/src/main/java/component/MustBeRefresh.java
index 3da2827..c14ee00 100644
--- a/src/main/java/component/MustBeRefresh.java
+++ b/src/main/java/component/MustBeRefresh.java
@@ -20,6 +20,7 @@ public class MustBeRefresh implements TlvComponentBase,InitialAble, IEncodingAbl
 
     public void setMustBeRefresh(boolean mustBeRefresh) {
         this.mustBeRefresh = mustBeRefresh;
+        this.doInitial();
     }
 
     // 接口实现-变量区
diff --git a/src/main/java/component/TTL.java b/src/main/java/component/TTL.java
index 7a1bb50..35fe92b 100644
--- a/src/main/java/component/TTL.java
+++ b/src/main/java/component/TTL.java
@@ -92,7 +92,7 @@ public class TTL implements IEncodingAble {
             return false;
         }
         long value=TLV.readNonNegativeInteger(block.getValue(),0,block.getLength().getVlIntValue2Int());
-        if(value==0){
+        if(value<0){
             return false;
         }
         this.ttl=value;
diff --git a/src/main/java/encoding/TLV.java b/src/main/java/encoding/TLV.java
index 0b059ac..4a55963 100644
--- a/src/main/java/encoding/TLV.java
+++ b/src/main/java/encoding/TLV.java
@@ -123,10 +123,10 @@ public class TLV {
      */
     public static long readNonNegativeInteger(byte[] buffer,int start,int end){
         if(start==end){
-            return 0;
+            return -1;
         }
         if((start<0)||(end>buffer.length)){
-            return 0;
+            return -1;
         }
         int len=end-start;
         byte[] bytes=new byte[len];
@@ -140,7 +140,7 @@ public class TLV {
         }else if(len==8){
             return ByteHelper.uint64ToLong(bytes);
         }else{
-            return 0;
+            return -1;
         }
     }