diff --git a/README.md b/README.md
index d835b661f..457914855 100644
--- a/README.md
+++ b/README.md
@@ -43,11 +43,14 @@ Currently, besides authorized DNS server of DNSPod, there are various products i
     # or NUMA
     echo 1024 > /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages
     echo 1024 > /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages
-	
+
     # Using Hugepage with the DPDK
     mkdir /mnt/huge
     mount -t hugetlbfs nodev /mnt/huge
-	
+
+    # close ASLR; it is necessary in multiple porcess
+    echo 0 > /proc/sys/kernel/randomize_va_space
+
     # offload NIC
     modprobe uio
     insmod /data/f-stack/dpdk/x86_64-native-linuxapp-gcc/build/kmod/igb_uio.ko
@@ -55,7 +58,7 @@ Currently, besides authorized DNS server of DNSPod, there are various products i
     python dpdk-devbind.py --status
     ifconfig eth0 down
     python dpdk-devbind.py --bind=igb_uio eth0 # assuming that use 10GE NIC and eth0
-	
+
     # Compile F-Stack
     cd ../../lib/
     make
diff --git a/config.ini b/config.ini
index e158fcda8..f5f8103b5 100644
--- a/config.ini
+++ b/config.ini
@@ -1,13 +1,17 @@
 [dpdk]
+## Hexadecimal bitmask of cores to run on.
 lcore_mask=3
 ## Port mask, enable and disable ports.
 ## Default: all ports are enabled.
 #port_mask=1
 channel=4
+## Number of ports.
 nb_ports=1
 promiscuous=1
 numa_on=1
 
+## Port config section
+## According to dpdk.nb_ports: port0, port1...
 [port0]
 addr=192.168.1.2
 netmask=255.255.255.0
@@ -15,6 +19,8 @@ broadcast=192.168.1.255
 gateway=192.168.1.1
 ## Packet capture path, this will hurt performance
 #pcap=./a.pcap
+## Strip vlan tag, such as EC2 etc.
+#vlanstrip=1
 
 ## Kni config: if enabled and method=reject,
 ## all packets that do not belong to the following tcp_port and udp_port
@@ -23,13 +29,9 @@ gateway=192.168.1.1
 #[kni]
 #enable=1
 #method=reject
-#tcp_port=80
+#tcp_port=80,443
 #udp_port=53
 
-[log]
-level=1
-dir=/var/log
-
 ## FreeBSD network performance tuning configurations.
 ## Most native FreeBSD configurations are supported.
 [freebsd.boot]
diff --git a/lib/ff_config.c b/lib/ff_config.c
index 5a09d092c..45080bad7 100644
--- a/lib/ff_config.c
+++ b/lib/ff_config.c
@@ -154,6 +154,8 @@ port_cfg_handler(struct ff_config *cfg, const char *section,
         cur->gateway = strdup(value);
     } else if (strcmp(name, "pcap") == 0) {
         cur->pcap = strdup(value);
+    } else if (strcmp(name, "vlanstrip") == 0) {
+        cur->vlanstrip = atoi(value);
     }
 
     return 1;
diff --git a/lib/ff_config.h b/lib/ff_config.h
index 837a2b1d9..08ad87bb2 100644
--- a/lib/ff_config.h
+++ b/lib/ff_config.h
@@ -38,6 +38,7 @@ struct ff_port_cfg {
     char *name;
     uint8_t port_id;
     uint8_t mac[6];
+    uint8_t vlanstrip;
     char *addr;
     char *netmask;
     char *broadcast;
diff --git a/lib/ff_dpdk_if.c b/lib/ff_dpdk_if.c
index b00394900..d932ed3d0 100644
--- a/lib/ff_dpdk_if.c
+++ b/lib/ff_dpdk_if.c
@@ -103,6 +103,8 @@ static struct rte_eth_conf default_port_conf = {
         .header_split   = 0, /**< Header Split disabled */
         .hw_ip_checksum = 0, /**< IP checksum offload disabled */
         .hw_vlan_filter = 0, /**< VLAN filtering disabled */
+        .hw_vlan_strip  = 0, /**< VLAN strip disabled. */
+        .hw_vlan_extend = 0, /**< Extended VLAN disabled. */
         .jumbo_frame    = 0, /**< Jumbo Frame Support disabled */
         .hw_strip_crc   = 0, /**< CRC stripped by hardware */
         .enable_lro     = 0, /**< LRO disabled */
@@ -561,6 +563,7 @@ init_port_start(void)
          * Set port conf according to dev's capability.
          */
         struct rte_eth_conf port_conf = default_port_conf;
+        port_conf.rxmode.hw_vlan_strip = ff_global_cfg.dpdk.port_cfgs[port_id].vlanstrip;
 
         /* Currently, proc id 1:1 map to queue id per port. */
         int ret = rte_eth_dev_configure(port_id, nb_procs, nb_procs, &port_conf);