diff --git a/net/Makefile.objs b/net/Makefile.objs
index 5fa2f97..95670f2 100644
--- a/net/Makefile.objs
+++ b/net/Makefile.objs
@@ -15,3 +15,4 @@ common-obj-$(CONFIG_VDE) += vde.o
 common-obj-$(CONFIG_NETMAP) += netmap.o
 common-obj-y += filter.o
 common-obj-y += filter-buffer.o
+common-obj-y += colo-proxy.o
diff --git a/net/colo-proxy.c b/net/colo-proxy.c
new file mode 100644
index 0000000..98c2699
--- /dev/null
+++ b/net/colo-proxy.c
@@ -0,0 +1,139 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2015 FUJITSU LIMITED
+ * Copyright (c) 2015 Intel Corporation
+ *
+ * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#include "colo-proxy.h"
+
+#define __DEBUG__
+
+#ifdef __DEBUG__
+#define DEBUG(format, ...) printf(format, ##__VA_ARGS__)
+#else
+#define DEBUG(format, ...)
+#endif
+
+
+static ssize_t colo_proxy_receive_iov(NetFilterState *nf,
+                                         NetClientState *sender,
+                                         unsigned flags,
+                                         const struct iovec *iov,
+                                         int iovcnt,
+                                         NetPacketSent *sent_cb)
+{
+    /*
+     * We return size when buffer a packet, the sender will take it as
+     * a already sent packet, so sent_cb should not be called later.
+     *
+     */
+    ColoProxyState *s = FILTER_COLO_PROXY(nf);
+    if (s->colo_mode == COLO_PRIMARY_MODE) {
+         /* colo_proxy_primary_handler */
+    } else {
+         /* colo_proxy_primary_handler */
+    }
+    return iov_size(iov, iovcnt);
+}
+
+static void colo_proxy_cleanup(NetFilterState *nf)
+{
+     /* cleanup */
+}
+
+
+static void colo_proxy_setup(NetFilterState *nf, Error **errp)
+{
+    ColoProxyState *s = FILTER_COLO_PROXY(nf);
+    if (!s->addr) {
+        error_setg(errp, "filter colo_proxy needs 'addr' \
+                     property set!");
+        return;
+    }
+
+    if (nf->direction != NET_FILTER_DIRECTION_ALL) {
+        printf("colo need queue all packet,\
+                    please startup colo-proxy with queue=all\n");
+        return;
+    }
+
+    s->sockfd = -1;
+    s->has_failover = false;
+    colo_do_checkpoint = false;
+    g_queue_init(&s->unprocessed_connections);
+
+    if (!strcmp(mode, PRIMARY_MODE)) {
+        s->colo_mode = COLO_PRIMARY_MODE;
+    } else if (!strcmp(mode, SECONDARY_MODE)) {
+        s->colo_mode = COLO_SECONDARY_MODE;
+    } else {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "mode",
+                    "primary or secondary");
+        return;
+    }
+}
+
+static void colo_proxy_class_init(ObjectClass *oc, void *data)
+{
+    NetFilterClass *nfc = NETFILTER_CLASS(oc);
+
+    nfc->setup = colo_proxy_setup;
+    nfc->cleanup = colo_proxy_cleanup;
+    nfc->receive_iov = colo_proxy_receive_iov;
+}
+
+static char *colo_proxy_get_mode(Object *obj, Error **errp)
+{
+    return g_strdup(mode);
+}
+
+static void colo_proxy_set_mode(Object *obj, const char *value, Error **errp)
+{
+    g_free(mode);
+    mode = g_strdup(value);
+}
+
+static char *colo_proxy_get_addr(Object *obj, Error **errp)
+{
+    ColoProxyState *s = FILTER_COLO_PROXY(obj);
+
+    return g_strdup(s->addr);
+}
+
+static void colo_proxy_set_addr(Object *obj, const char *value, Error **errp)
+{
+    ColoProxyState *s = FILTER_COLO_PROXY(obj);
+    g_free(s->addr);
+    s->addr = g_strdup(value);
+}
+
+static void colo_proxy_init(Object *obj)
+{
+    object_property_add_str(obj, "mode", colo_proxy_get_mode,
+                            colo_proxy_set_mode, NULL);
+    object_property_add_str(obj, "addr", colo_proxy_get_addr,
+                            colo_proxy_set_addr, NULL);
+}
+
+static const TypeInfo colo_proxy_info = {
+    .name = TYPE_FILTER_COLO_PROXY,
+    .parent = TYPE_NETFILTER,
+    .class_init = colo_proxy_class_init,
+    .instance_init = colo_proxy_init,
+    .instance_size = sizeof(ColoProxyState),
+};
+
+static void register_types(void)
+{
+    type_register_static(&colo_proxy_info);
+}
+
+type_init(register_types);
diff --git a/net/colo-proxy.h b/net/colo-proxy.h
new file mode 100644
index 0000000..94afbc7
--- /dev/null
+++ b/net/colo-proxy.h
@@ -0,0 +1,63 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2015 FUJITSU LIMITED
+ * Copyright (c) 2015 Intel Corporation
+ *
+ * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+
+#ifndef QEMU_COLO_PROXY_H
+#define QEMU_COLO_PROXY_H
+
+#include "net/filter.h"
+#include "net/queue.h"
+#include "qemu-common.h"
+#include "qemu/iov.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi-visit.h"
+#include "qom/object.h"
+#include "qemu/sockets.h"
+#include "qemu/main-loop.h"
+#include <netinet/if_ether.h>
+#include "qemu/jhash.h"
+#include "qemu/coroutine.h"
+
+#define FILTER_COLO_PROXY(obj) \
+    OBJECT_CHECK(ColoProxyState, (obj), TYPE_FILTER_COLO_PROXY)
+
+#define TYPE_FILTER_COLO_PROXY "colo-proxy"
+#define PRIMARY_MODE "primary"
+#define SECONDARY_MODE "secondary"
+
+typedef enum {
+    COLO_PRIMARY_MODE,               /* primary mode  */
+    COLO_SECONDARY_MODE,             /* secondary mode */
+} mode_type;
+
+typedef struct ColoProxyState {
+    NetFilterState parent_obj;
+    NetQueue *incoming_queue;        /* guest normal net queue */
+    NetFilterDirection direction;    /* packet direction */
+    mode_type colo_mode;             /* colo mode (primary or
+                                      * secondary)
+                                      */
+    char *addr;                       /* primary colo connect addr
+                                      * or secondary server addr
+                                      */
+    int sockfd;                      /* primary client socket fd or
+                                      * secondary server socket fd
+                                      */
+    bool has_failover;               /* colo failover flag */
+    GHashTable *unprocessed_packets; /* hashtable to save connection */
+    GQueue unprocessed_connections;  /* to save unprocessed_connections */
+    Coroutine *co;
+} ColoProxyState;
+
+#endif /* QEMU_COLO_PROXY_H */
