diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h
index 3b37867..6e40c32 100644
--- a/include/polarssl/ssl.h
+++ b/include/polarssl/ssl.h
@@ -876,6 +876,14 @@
 #endif
 
     /*
+     * Client id (IP/port) for DTLS hello verify
+     */
+#if defined(POLARSSL_SSL_PROTO_DTLS) && defined(POLARSSL_SSL_SRV_C)
+    unsigned char  *cli_id;         /*!<  transport-level ID of the client  */
+    size_t          cli_id_len;     /*!<  length of cli_id                  */
+#endif
+
+    /*
      * Secure renegotiation
      */
     int secure_renegotiation;           /*!<  does peer support legacy or
@@ -1058,6 +1066,33 @@
         int (*f_recv)(void *, unsigned char *, size_t), void *p_recv,
         int (*f_send)(void *, const unsigned char *, size_t), void *p_send );
 
+#if defined(POLARSSL_SSL_PROTO_DTLS) && defined(POLARSSL_SSL_SRV_C)
+/**
+ * \brief          Set client's transport-level identification info.
+ *                 (Only usable on server.)
+ *
+ *                 This is usually the IP address (and port), but could be
+ *                 anything identify the client depending on the underlying
+ *                 network stack. Used for HelloVerifyRequest with DTLS.
+ *                 This is *not* used to route the actual packets.
+ *
+ * \warning (TODO-DTLS) May change and even be removed before 2.0.0!
+ *
+ * \param ssl      SSL context
+ * \param info     Transport-level info identifying the client (eg IP + port)
+ * \param ilen     Length of info in bytes
+ *
+ * \note           An internal copy is made, so the info buffer can be reused.
+ *
+ * \return         0 on success,
+ *                 POLARSSL_ERR_SSL_BAD_INPUT_DATA if used on client,
+ *                 POLARSSL_ERR_SSL_MALLOC_FAILED if out of memory.
+ */
+int ssl_set_client_transport_id( ssl_context *ssl,
+                                 const unsigned char *info,
+                                 size_t ilen );
+#endif /* POLARSSL_SSL_PROTO_DTLS && POLARSSL_SSL_SRV_C */
+
 /**
  * \brief          Set the session cache callbacks (server-side only)
  *                 If not set, no session resuming is done.
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 430f51a..eac553f 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -351,6 +351,26 @@
 }
 #endif /* POLARSSL_SSL_SESSION_TICKETS */
 
+#if defined(POLARSSL_SSL_PROTO_DTLS)
+int ssl_set_client_transport_id( ssl_context *ssl,
+                                 const unsigned char *info,
+                                 size_t ilen )
+{
+    if( ssl->endpoint != SSL_IS_SERVER )
+        return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+    polarssl_free( ssl->cli_id );
+
+    if( ( ssl->cli_id = polarssl_malloc( ilen ) ) == NULL )
+        return( POLARSSL_ERR_SSL_MALLOC_FAILED );
+
+    memcpy( ssl->cli_id, info, ilen );
+    ssl->cli_id_len = ilen;
+
+    return( 0 );
+}
+#endif /* POLARSSL_SSL_PROTO_DTLS */
+
 #if defined(POLARSSL_SSL_SERVER_NAME_INDICATION)
 /*
  * Wrapper around f_sni, allowing use of ssl_set_own_cert() but
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 27ee058..d854199 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3749,6 +3749,12 @@
     ssl->alpn_chosen = NULL;
 #endif
 
+#if defined(POLARSSL_SSL_PROTO_DTLS) && defined(POLARSSL_SSL_SRV_C)
+    polarssl_free( ssl->cli_id );
+    ssl->cli_id = NULL;
+    ssl->cli_id_len = 0;
+#endif
+
     if( ( ret = ssl_handshake_init( ssl ) ) != 0 )
         return( ret );
 
@@ -5033,6 +5039,10 @@
     }
 #endif
 
+#if defined(POLARSSL_SSL_PROTO_DTLS) && defined(POLARSSL_SSL_SRV_C)
+    polarssl_free( ssl->cli_id );
+#endif
+
     SSL_DEBUG_MSG( 2, ( "<= free" ) );
 
     /* Actually clear after last debug message */