diff --git a/examples/stm32/nucleo-f746zg-baremetal/Makefile b/examples/stm32/nucleo-f746zg-baremetal/Makefile
index 1d3db013..75c647ed 100644
--- a/examples/stm32/nucleo-f746zg-baremetal/Makefile
+++ b/examples/stm32/nucleo-f746zg-baremetal/Makefile
@@ -34,7 +34,7 @@ DEVICE_URL ?= https://dash.vcon.io/api/v3/devices/5
 update: firmware.bin
 	curl --fail-with-body -su :$(VCON_API_KEY) $(DEVICE_URL)/ota --data-binary @$<
 
-test: CFLAGS_EXTRA += -DUART_DEBUG=USART1
+test update: CFLAGS_EXTRA += -DUART_DEBUG=USART1
 test: update
 	curl --fail-with-body -su :$(VCON_API_KEY) $(DEVICE_URL)/tx?t=5 | tee /tmp/output.txt
 	grep 'READY, IP:' /tmp/output.txt       # Check for network init
diff --git a/mongoose.c b/mongoose.c
index 3422555c..3ed21ec5 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -7810,6 +7810,7 @@ static void mg_tcpip_rx(struct mg_tcpip_if *ifp, void *buf, size_t len) {
     rx_ip(ifp, &pkt);
   } else {
     MG_DEBUG(("  Unknown eth type %x", mg_htons(pkt.eth->type)));
+    mg_hexdump(buf, len >= 16 ? 16 : len);
   }
 }
 
@@ -7907,8 +7908,9 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
     mgr->extraconnsize = sizeof(struct connstate);
     if (ifp->ip == 0) ifp->enable_dhcp_client = true;
     memset(ifp->gwmac, 255, sizeof(ifp->gwmac));  // Set to broadcast
-    mg_random(&ifp->eport, sizeof(ifp->eport));   // Randomise the initial
-    ifp->eport += MG_EPHEMERAL_PORT_BASE;         // ephemeral port
+    mg_random(&ifp->eport, sizeof(ifp->eport));   // Random from 0 to 65535
+    ifp->eport |=
+        MG_EPHEMERAL_PORT_BASE;  // Random from MG_EPHEMERAL_PORT_BASE to 65535
   }
 }
 
diff --git a/src/tcpip/tcpip.c b/src/tcpip/tcpip.c
index 9ae0ef07..0e6f1728 100644
--- a/src/tcpip/tcpip.c
+++ b/src/tcpip/tcpip.c
@@ -759,6 +759,7 @@ static void mg_tcpip_rx(struct mg_tcpip_if *ifp, void *buf, size_t len) {
     rx_ip(ifp, &pkt);
   } else {
     MG_DEBUG(("  Unknown eth type %x", mg_htons(pkt.eth->type)));
+    mg_hexdump(buf, len >= 16 ? 16 : len);
   }
 }
 
@@ -856,8 +857,9 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
     mgr->extraconnsize = sizeof(struct connstate);
     if (ifp->ip == 0) ifp->enable_dhcp_client = true;
     memset(ifp->gwmac, 255, sizeof(ifp->gwmac));  // Set to broadcast
-    mg_random(&ifp->eport, sizeof(ifp->eport));   // Randomise the initial
-    ifp->eport += MG_EPHEMERAL_PORT_BASE;         // ephemeral port
+    mg_random(&ifp->eport, sizeof(ifp->eport));   // Random from 0 to 65535
+    ifp->eport |=
+        MG_EPHEMERAL_PORT_BASE;  // Random from MG_EPHEMERAL_PORT_BASE to 65535
   }
 }