diff --git a/src/router.c b/src/router.c
index 6b2c737..327dc5a 100644
--- a/src/router.c
+++ b/src/router.c
@@ -204,7 +204,14 @@ DWORD router_main(void *arg) {
 			continue;
 		}
 		
-		add_host(packet->src_net, packet->src_node, addr.sin_addr.s_addr);
+		/* Replace destination network field of packet with source IP address
+		 * so that the client can cache it.
+		*/
+		
+		char dest_net[4];
+		
+		memcpy(dest_net, packet->dest_net, 4);
+		memcpy(packet->dest_net, &(addr.sin_addr.s_addr), 4);
 		
 		struct router_addr *ra = router->addrs;
 		
@@ -212,7 +219,7 @@ DWORD router_main(void *arg) {
 			if(
 				ra->local_port &&
 				(ra->filter_ptype < 0 || ra->filter_ptype == packet->ptype) &&
-				(memcmp(packet->dest_net, ra->addr.sa_netnum, 4) == 0 || memcmp(packet->dest_net, f6, 4) == 0) &&
+				(memcmp(dest_net, ra->addr.sa_netnum, 4) == 0 || memcmp(dest_net, f6, 4) == 0) &&
 				(memcmp(packet->dest_node, ra->addr.sa_nodenum, 6) == 0 || memcmp(packet->dest_node, f6, 6) == 0) &&
 				packet->dest_socket == ra->addr.sa_socket
 			) {
diff --git a/src/winsock.c b/src/winsock.c
index 5d7bd50..6eb330e 100644
--- a/src/winsock.c
+++ b/src/winsock.c
@@ -322,6 +322,17 @@ static int recv_packet(ipx_socket *sockptr, char *buf, int bufsize, int flags, s
 		return -1;
 	}
 	
+	if(rval < sizeof(ipx_packet) || rval != packet->size + sizeof(ipx_packet) - 1) {
+		log_printf("Invalid packet received on loopback port!");
+		
+		free(packet);
+		WSASetLastError(WSAEWOULDBLOCK);
+		return -1;
+	}
+	
+	/* Router thread replaces destination network number with source IP address */
+	add_host(packet->src_net, packet->src_node, *((uint32_t*)packet->dest_net));
+	
 	if(addr) {
 		addr->sa_family = AF_IPX;
 		memcpy(addr->sa_netnum, packet->src_net, 4);