diff --git a/linux/README.md b/linux/README.md
index 1fcb4c4..5ff62e9 100644
--- a/linux/README.md
+++ b/linux/README.md
@@ -19,10 +19,14 @@ IP address and switch the interface on.
 For example:
 
     /root/esptun tun0 /dev/ttyS1 "accesspointname" "secretpassword" 192.168.122.21 23232
+    /sbin/ip link set dev tun0 mtu 1472
     /sbin/ip addr add 10.0.1.2/24 dev tun0
     /sbin/ip link set tun0 up
     /sbin/ip route add default via 10.0.1.1 dev tun0
 
+(setting the MTU to `1500-20-8` the typical network MTU minus IP and UDP header overhead, because
+otherwise the ESP's network stack will drop the oversized packets)
+
 Host side
 ---------
 
@@ -30,7 +34,8 @@ On the other endpoint the tunnel is expected to be a host running `socat` or sim
 the tunnel. For example:
 
     sudo socat UDP:192.168.2.127:23232,bind=192.168.122.21:23232 \
-        TUN:10.0.1.1/24,tun-name=tundudp,iff-no-pi,tun-type=tun,su=$USER,iff-up
+        TUN:10.0.1.1/24,tun-name=tundudp,iff-no-pi,tun-type=tun,su=$USER,iff-up &
+    sudo ip link set dev tundudp mtu 1472
 
 Optionally, enable forwarding and masquerading:
 
diff --git a/linux/esptun.c b/linux/esptun.c
index 681f740..7285b39 100644
--- a/linux/esptun.c
+++ b/linux/esptun.c
@@ -395,12 +395,12 @@ static bool esp_read_responses(int fd, bool early_terminate)
 }
 
 /** Send a packet to ESP interface. */
-static void esp_tx_packet(int fd, const uint8_t *esp_buffer, size_t size) {
+static void esp_tx_packet(int fd, const uint8_t *buffer, size_t size) {
     write_all(fd, S("AT+CIPSEND="));
     write_uint(fd, size);
     write_all(fd, S("\r\n"));
     if (esp_read_responses(fd, false)) {
-        write_all(fd, esp_buffer, size);
+        write_all(fd, buffer, size);
         esp_read_responses(fd, false);
     }
 }