diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,11 @@
+## 0.1.17
+
+- Garding the new_connection_id attack.
+
+## 0.1.16
+
+- Using tls v2.0.
+
 ## 0.1.15
 
 - Support customizing ClientHooks and ServerHooks config from tls
diff --git a/Network/QUIC/Connection/Misc.hs b/Network/QUIC/Connection/Misc.hs
--- a/Network/QUIC/Connection/Misc.hs
+++ b/Network/QUIC/Connection/Misc.hs
@@ -26,7 +26,7 @@
     readMinIdleTimeout,
     setMinIdleTimeout,
     sendFrames,
-    sendFrames1,
+    sendFramesLim,
     closeConnection,
     abortConnection,
 ) where
@@ -176,8 +176,8 @@
 sendFrames :: Connection -> EncryptionLevel -> [Frame] -> IO ()
 sendFrames conn lvl frames = putOutput conn $ OutControl lvl frames $ return ()
 
-sendFrames1 :: Connection -> EncryptionLevel -> [Frame] -> IO ()
-sendFrames1 conn lvl frames = putOutput1 conn $ OutControl lvl frames $ return ()
+sendFramesLim :: Connection -> EncryptionLevel -> [Frame] -> IO ()
+sendFramesLim conn lvl frames = putOutputLim conn $ OutControl lvl frames $ return ()
 
 -- | Closing a connection with/without a transport error.
 --   Internal threads should use this.
diff --git a/Network/QUIC/Connection/Queue.hs b/Network/QUIC/Connection/Queue.hs
--- a/Network/QUIC/Connection/Queue.hs
+++ b/Network/QUIC/Connection/Queue.hs
@@ -31,14 +31,17 @@
 putOutput :: Connection -> Output -> IO ()
 putOutput conn out = atomically $ writeTQueue (outputQ conn) out
 
-putOutput1 :: Connection -> Output -> IO ()
-putOutput1 conn out = atomically $ do
-    ok <- isEmptyTBQueue (outputQ1 conn)
+outputLimit :: Int
+outputLimit = 10
+
+putOutputLim :: Connection -> Output -> IO ()
+putOutputLim conn out = atomically $ do
+    len <- fromIntegral <$> lengthTBQueue (outputQLim conn)
     -- unless ok, the frames are intentionally dropped.
-    when ok $ writeTBQueue (outputQ1 conn) out
+    when (len < outputLimit) $ writeTBQueue (outputQLim conn) out
 
 takeOutput1STM :: Connection -> STM Output
-takeOutput1STM conn = readTBQueue (outputQ1 conn)
+takeOutput1STM conn = readTBQueue (outputQLim conn)
 
 ----------------------------------------------------------------
 
diff --git a/Network/QUIC/Connection/Types.hs b/Network/QUIC/Connection/Types.hs
--- a/Network/QUIC/Connection/Types.hs
+++ b/Network/QUIC/Connection/Types.hs
@@ -217,7 +217,7 @@
       inputQ :: InputQ
     , cryptoQ :: CryptoQ
     , outputQ :: OutputQ
-    , outputQ1 :: OutputQ1
+    , outputQLim :: OutputQLim
     , migrationQ :: MigrationQ
     , shared :: Shared
     , delayedAckCount :: IORef Int
@@ -417,7 +417,7 @@
 type InputQ = TQueue Input
 type CryptoQ = TQueue Crypto
 type OutputQ = TQueue Output
-type OutputQ1 = TBQueue Output
+type OutputQLim = TBQueue Output
 type MigrationQ = TQueue ReceivedPacket
 
 ----------------------------------------------------------------
diff --git a/Network/QUIC/Receiver.hs b/Network/QUIC/Receiver.hs
--- a/Network/QUIC/Receiver.hs
+++ b/Network/QUIC/Receiver.hs
@@ -255,7 +255,7 @@
         Nothing -> do
             when (isInitiated conn sid) $
                 closeConnection StreamStateError "No such stream for STOP_SENDING"
-        Just _strm -> sendFrames conn lvl [ResetStream sid err 0]
+        Just _strm -> sendFramesLim conn lvl [ResetStream sid err 0]
 processFrame _ _ (CryptoF _ "") = return ()
 processFrame conn lvl (CryptoF off cdat) = do
     when (lvl == RTT0Level) $
@@ -373,7 +373,7 @@
         closeConnection FrameEncodingError "NEW_CONNECTION_ID parameter error"
     when (rpt >= 1) $ do
         seqNums <- setPeerCIDAndRetireCIDs conn rpt
-        sendFrames conn RTT1Level $ map RetireConnectionID seqNums
+        sendFramesLim conn RTT1Level $ map RetireConnectionID seqNums
 processFrame conn RTT1Level (RetireConnectionID sn) = do
     mcidInfo <- retireMyCID conn sn
     case mcidInfo of
@@ -383,7 +383,7 @@
                 unregister <- getUnregister conn
                 unregister cid
 processFrame conn RTT1Level (PathChallenge dat) =
-    sendFrames1 conn RTT1Level [PathResponse dat]
+    sendFramesLim conn RTT1Level [PathResponse dat]
 processFrame conn RTT1Level (PathResponse dat) =
     -- RTT0Level falls intentionally
     checkResponse conn dat
diff --git a/Network/QUIC/Types/Frame.hs b/Network/QUIC/Types/Frame.hs
--- a/Network/QUIC/Types/Frame.hs
+++ b/Network/QUIC/Types/Frame.hs
@@ -107,9 +107,11 @@
 inFlight _                    = True
 
 rateControled :: Frame -> Bool
-rateControled ResetStream{}   = True
-rateControled StopSending{}   = True
-rateControled PathChallenge{} = True
-rateControled PathResponse{}  = True
-rateControled _               = False
+rateControled ResetStream{}        = True
+rateControled StopSending{}        = True
+rateControled PathChallenge{}      = True
+rateControled PathResponse{}       = True
+rateControled NewConnectionID{}    = True
+rateControled RetireConnectionID{} = True
+rateControled _                    = False
 {- FOURMOLU_ENABLE -}
diff --git a/quic.cabal b/quic.cabal
--- a/quic.cabal
+++ b/quic.cabal
@@ -1,6 +1,6 @@
 cabal-version:      >=1.10
 name:               quic
-version:            0.1.16
+version:            0.1.17
 license:            BSD3
 license-file:       LICENSE
 maintainer:         kazu@iij.ad.jp
@@ -139,7 +139,7 @@
         stm >= 2.5 && < 2.6,
         data-default-class >= 0.1.2 && < 0.2,
         fast-logger >= 3.2.2 && < 3.3,
-        unix-time >= 0.4.11 && < 0.5,
+        unix-time >= 0.4.12 && < 0.5,
         iproute >= 1.7.12 && < 1.8,
         network >= 3.1.4 && < 3.2,
         network-byte-order >= 0.1.7 && < 0.2,