diff --git a/components/lwip/api/lwip_debug.c b/components/lwip/api/lwip_debug.c
new file mode 100644
index 000000000..1e5fed40d
--- /dev/null
+++ b/components/lwip/api/lwip_debug.c
@@ -0,0 +1,126 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "lwip/lwip_debug.h"
+#include "lwip/api.h"
+#include "lwip/netbuf.h"
+#include "lwip/tcp.h"
+#include "lwip/udp.h"
+#include "lwip/priv/tcp_priv.h"
+
+#define DBG_LWIP_IP_SHOW(info, ip)  printf("%s type=%d ip=%x\n", (info), (ip).type, (ip).u_addr.ip4.addr)
+#define DBG_LWIP_IP_PCB_SHOW(pcb) \
+        DBG_LWIP_IP_SHOW("local ip", (pcb)->local_ip);\
+        DBG_LWIP_IP_SHOW("remote ip", (pcb)->local_ip);\
+        printf("so_options=%x, tos=%d ttl=%d\n", (pcb)->so_options, (pcb)->tos, (pcb)->ttl)
+
+#define DBG_LWIP_SEG_SHOW(seg) while(seg) { printf("\tseg=%p next=%p pbuf=%p flags=%x\n", (seg), (seg)->next, (seg)->p, (seg)->flags); (seg)=(seg)->next;}
+    
+
+static void dbg_lwip_tcp_pcb_one_show(struct tcp_pcb* pcb)
+{
+    struct tcp_seg *seg = NULL;
+
+    if (!pcb) {
+        return;
+    }
+
+    printf("\npcb=%p next=%p cb_arg=%p\n", pcb, pcb->next, pcb->callback_arg);
+    DBG_LWIP_IP_PCB_SHOW(pcb);
+    printf("state=%x\n", pcb->state);
+    printf("prio=%d\n", pcb->prio);
+    printf("local_port=%d, remote_port=%d\n", pcb->local_port, pcb->remote_port);
+    printf("flags=%x\n", pcb->flags);
+    printf("pooltmr=%d pollinterval=%d, last_tmr=%d tmr=%d rtmer=%d\n", pcb->polltmr, pcb->pollinterval, pcb->last_timer, pcb->tmr, pcb->rtime);
+    printf("recv_nxt=%d recv_wnd=%d recv_ann_wnd=%d recv_ann_right_edge=%d\n", pcb->rcv_nxt, pcb->rcv_wnd, pcb->rcv_ann_wnd, pcb->rcv_ann_right_edge);
+    printf("mss=%d\n", pcb->mss);
+    printf("rttest=%d rtseq=%d sa=%d sv=%d\n", pcb->rttest, pcb->rtseq, pcb->sa, pcb->sv);
+    printf("rto=%d nrtx=%d\n", pcb->rto, pcb->nrtx);
+    printf("dupacks=%d lastack=%d\n", pcb->dupacks, pcb->lastack);
+    printf("cwnd=%d ssthreash=%d\n", pcb->cwnd, pcb->ssthresh);
+    printf("snd_next=%d snd_wl1=%d snd_wl2=%d\n", pcb->snd_nxt, pcb->snd_wl1, pcb->snd_wl2);
+    printf("snd_lbb=%d snd_wnd=%d snd_wnd_max=%d\n", pcb->snd_lbb, pcb->snd_wnd, pcb->snd_wnd_max);
+    printf("acked=%d\n", pcb->acked);
+    printf("snd_buf=%d snd_queuelen=%d\n", pcb->snd_buf, pcb->snd_queuelen);
+    printf("unsent_oversize=%d\n", pcb->unsent_oversize);
+    printf("keep_idle=%d keep_intvl=%d keep_cnt=%d\n", pcb->keep_idle, pcb->keep_intvl, pcb->keep_cnt);
+    printf("persist_cnt=%d persist_backoff=%d\n", pcb->persist_cnt, pcb->persist_backoff);
+    printf("keep_cnt_sent=%d\n", pcb->keep_cnt_sent);
+
+    printf("unsent segments:\n");
+    seg = pcb->unsent;
+    DBG_LWIP_SEG_SHOW(seg) 
+
+    printf("unacked segments:\n");
+    seg = pcb->unacked;
+    DBG_LWIP_SEG_SHOW(seg);
+
+    printf("ooseg semengts:\n");
+    seg = pcb->ooseq;
+    DBG_LWIP_SEG_SHOW(seg);
+
+    printf("refused data=%p\n", pcb->refused_data);
+}
+
+static void dbg_lwip_tcp_pcb_list_show(struct tcp_pcb* pcb)
+{
+    while(pcb){
+        dbg_lwip_tcp_pcb_one_show(pcb);
+        pcb = pcb->next;
+    }
+}
+
+extern struct tcp_pcb *tcp_bound_pcbs;
+extern struct tcp_pcb *tcp_active_pcbs;
+extern struct tcp_pcb *tcp_tw_pcbs;
+void dbg_lwip_tcp_pcb_show(void)
+{
+    printf("-------------active pcbs------------\n");
+    dbg_lwip_tcp_pcb_list_show(tcp_active_pcbs);
+    printf("-------------bound pcbs-------------\n");
+    dbg_lwip_tcp_pcb_list_show(tcp_bound_pcbs);
+    printf("-------------tw     pcbs------------\n");
+    dbg_lwip_tcp_pcb_list_show(tcp_tw_pcbs);
+}
+
+void dbg_lwip_udp_pcb_one_show(struct udp_pcb *pcb)
+{
+    printf("pcb=%p next=%p\n", pcb, (void*)pcb->next);
+    DBG_LWIP_IP_PCB_SHOW(pcb);
+    printf("flags=%x\n", pcb->flags);
+    printf("local_port=%d remote_port=%d\n", pcb->local_port, pcb->remote_port);
+    printf("recv cb=%p recv_arg=%p\n", pcb->recv, pcb->recv_arg);
+}
+
+extern struct udp_pcb *udp_pcbs;
+void dbg_lwip_udp_pcb_show(void)
+{
+    struct udp_pcb *pcb = udp_pcbs;
+
+    while (pcb){
+        dbg_lwip_udp_pcb_one_show(pcb);
+        pcb = pcb->next;
+    }
+}
+
+void dbg_lwip_tcp_rxtx_show(void)
+{
+    printf("TBC\n");
+}
+
+void dbg_lwip_udp_rxtx_show(void)
+{
+    printf("TBC\n");
+}
+
diff --git a/components/lwip/include/lwip/lwip/lwip_debug.h b/components/lwip/include/lwip/lwip/lwip_debug.h
new file mode 100644
index 000000000..abfcd2c1c
--- /dev/null
+++ b/components/lwip/include/lwip/lwip/lwip_debug.h
@@ -0,0 +1,24 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#ifndef _LWIP_DEBUG_H
+#define _LWIP_DEBUG_H
+
+void dbg_lwip_tcp_pcb_show(void);
+void dbg_lwip_udp_pcb_show(void);
+void dbg_lwip_tcp_rxtx_show(void);
+void dbg_lwip_udp_rxtx_show(void);
+
+#endif