Index: head/sys/dev/hyperv/netvsc/hv_net_vsc.h
===================================================================
--- head/sys/dev/hyperv/netvsc/hv_net_vsc.h
+++ head/sys/dev/hyperv/netvsc/hv_net_vsc.h
@@ -857,7 +857,7 @@
 #define NETVSC_SEND_BUFFER_SIZE			(1024*1024*15)   /* 15M */
 #define NETVSC_SEND_BUFFER_ID			0xface
 
-
+#define NETVSC_RECEIVE_BUFFER_SIZE_LEGACY	(1024*1024*15) /* 15MB */
 #define NETVSC_RECEIVE_BUFFER_SIZE		(1024*1024*16) /* 16MB */
 
 #define NETVSC_RECEIVE_BUFFER_ID		0xcafe
Index: head/sys/dev/hyperv/netvsc/hv_net_vsc.c
===================================================================
--- head/sys/dev/hyperv/netvsc/hv_net_vsc.c
+++ head/sys/dev/hyperv/netvsc/hv_net_vsc.c
@@ -642,6 +642,12 @@
 	/* sema_wait(&NetVscChannel->channel_init_sema); */
 
 	/* Post the big receive buffer to NetVSP */
+	if (net_dev->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
+		net_dev->rx_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
+	else
+		net_dev->rx_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
+	net_dev->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
+
 	ret = hv_nv_init_rx_buffer_with_net_vsp(device);
 	if (ret == 0)
 		ret = hv_nv_init_send_buffer_with_net_vsp(device);
@@ -676,9 +682,6 @@
 		goto cleanup;
 
 	/* Initialize the NetVSC channel extension */
-	net_dev->rx_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
-
-	net_dev->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 
 	sema_init(&net_dev->channel_init_sema, 0, "netdev_sema");