Index: uspace/lib/net/il/ip_client.c
===================================================================
--- uspace/lib/net/il/ip_client.c	(revision d4c472baf92535da28ffed49127c8526791c168f)
+++ uspace/lib/net/il/ip_client.c	(revision 40ffda8c66dc2c631d4b6944acb463ef338a5926)
@@ -181,6 +181,6 @@
 	/* Set the header */
 	header = (ip_header_t *) data;
-	header->header_length = IP_COMPUTE_HEADER_LENGTH(sizeof(ip_header_t) +
-	    ipopt_length);
+	SET_HEADER_LENGTH(header, (IP_COMPUTE_HEADER_LENGTH(sizeof(ip_header_t)
+        + ipopt_length)));
 	header->ttl = (ttl ? ttl : IPDEFTTL);
 	header->tos = tos;
@@ -188,5 +188,5 @@
 
 	if (dont_fragment)
-		header->flags = IPFLAG_DONT_FRAGMENT;
+		SET_HEADER_FLAGS(header, IPFLAG_DONT_FRAGMENT);
 
 	return EOK;
@@ -227,5 +227,5 @@
 		*tos = header->tos;
 	if (dont_fragment)
-		*dont_fragment = header->flags & IPFLAG_DONT_FRAGMENT;
+		*dont_fragment = GET_HEADER_FLAGS(header) & IPFLAG_DONT_FRAGMENT;
 	if (ipopt_length) {
 		*ipopt_length = IP_HEADER_LENGTH(header) - sizeof(ip_header_t);
Index: uspace/lib/net/include/ip_header.h
===================================================================
--- uspace/lib/net/include/ip_header.h	(revision d4c472baf92535da28ffed49127c8526791c168f)
+++ uspace/lib/net/include/ip_header.h	(revision 40ffda8c66dc2c631d4b6944acb463ef338a5926)
@@ -64,5 +64,5 @@
  */
 #define IP_FRAGMENT_OFFSET(header) \
-	((((header)->fragment_offset_high << 8) + \
+	(((GET_HEADER_FRAGMENT_OFFSET_HIGH(header) << 8) + \
 	    (header)->fragment_offset_low) * 8U)
 
@@ -83,5 +83,5 @@
  */
 #define IP_HEADER_LENGTH(header) \
-	((header)->header_length * 4U)
+	(GET_HEADER_LENGTH(header) * 4U)
 
 /** Returns the actual IP packet total length.
@@ -143,11 +143,17 @@
  */
 struct ip_header {
-#ifdef ARCH_IS_BIG_ENDIAN
-	uint8_t version : 4;
-	uint8_t header_length : 4;
-#else
-	uint8_t header_length : 4;
-	uint8_t version : 4;
-#endif
+	uint8_t vhl; /* version, header_length */
+
+#define GET_HEADER_VERSION(header) \
+	(((header)->vhl & 0xf0) >> 4)
+#define SET_HEADER_VERSION(header, version) \
+	((header)->vhl = \
+	 ((version & 0x0f) << 4) | ((header)->vhl & 0x0f))
+
+#define GET_HEADER_LENGTH(header) \
+	((header)->vhl & 0x0f)
+#define SET_HEADER_LENGTH(header, length) \
+	((header)->vhl = \
+	 (length & 0x0f) | ((header)->vhl & 0xf0))
 
 	uint8_t tos;
@@ -155,11 +161,17 @@
 	uint16_t identification;
 
-#ifdef ARCH_IS_BIG_ENDIAN
-	uint8_t flags : 3;
-	uint8_t fragment_offset_high : 5;
-#else
-	uint8_t fragment_offset_high : 5;
-	uint8_t flags : 3;
-#endif
+	uint8_t ffoh; /* flags, fragment_offset_high */
+
+#define GET_HEADER_FLAGS(header) \
+	(((header)->ffoh & 0xe0) >> 5)
+#define SET_HEADER_FLAGS(header, flags) \
+	((header)->ffoh = \
+	 ((flags & 0x07) << 5) | ((header)->ffoh & 0x1f))
+
+#define GET_HEADER_FRAGMENT_OFFSET_HIGH(header) \
+	((header)->ffoh & 0x1f)
+#define SET_HEADER_FRAGMENT_OFFSET_HIGH(header, fragment_offset_high) \
+	((header)->ffoh = \
+	 (fragment_offset_high & 0x1f) | ((header)->ffoh & 0xe0))
 
 	uint8_t fragment_offset_low;
@@ -181,11 +193,18 @@
 	uint8_t pointer;
 
-#ifdef ARCH_IS_BIG_ENDIAN
-	uint8_t overflow : 4;
-	uint8_t flags : 4;
-#else
-	uint8_t flags : 4;
-	uint8_t overflow : 4;
-#endif
+	uint8_t of; /* overflow, flags */
+
+#define GET_OPTION_OVERFLOW(option) \
+	(((option)->of & 0xf0) >> 4)
+#define SET_OPTION_OVERFLOW(option, overflow) \
+	((option)->of = \
+	 ((overflow & 0x0f) << 4) | ((option)->of & 0x0f))
+
+#define GET_OPTION_FLAGS(option) \
+	((option)->of & 0x0f)
+#define SET_OPTION_FLAGS(option, flags) \
+	((option)->of = \
+	 (flags & 0x0f) | ((option)->of & 0xf0))
+
 } __attribute__ ((packed));
 
Index: uspace/srv/net/il/ip/ip.c
===================================================================
--- uspace/srv/net/il/ip/ip.c	(revision d4c472baf92535da28ffed49127c8526791c168f)
+++ uspace/srv/net/il/ip/ip.c	(revision 40ffda8c66dc2c631d4b6944acb463ef338a5926)
@@ -201,5 +201,5 @@
 
 	/* Set the destination address */
-	switch (header->version) {
+	switch (GET_HEADER_VERSION(header)) {
 	case IPVERSION:
 		addrlen = sizeof(dest_in);
@@ -635,5 +635,5 @@
 
 	/* Process all IP options */
-	while (next < first->header_length) {
+	while (next < GET_HEADER_LENGTH(first)) {
 		option = (ip_option_t *) (((uint8_t *) first) + next);
 		/* Skip end or noop */
@@ -656,7 +656,7 @@
 	if (length % 4) {
 		bzero(((uint8_t *) last) + length, 4 - (length % 4));
-		last->header_length = length / 4 + 1;
+		SET_HEADER_LENGTH(last, (length / 4 + 1));
 	} else {
-		last->header_length = length / 4;
+		SET_HEADER_LENGTH(last, (length / 4));
 	}
 
@@ -706,6 +706,6 @@
 		return rc;
 	
-	header->version = IPV4;
-	header->fragment_offset_high = 0;
+	SET_HEADER_VERSION(header, IPV4);
+	SET_HEADER_FRAGMENT_OFFSET_HIGH(header, 0);
 	header->fragment_offset_low = 0;
 	header->header_checksum = 0;
@@ -735,9 +735,10 @@
 			memcpy(middle_header, last_header,
 			    IP_HEADER_LENGTH(last_header));
-			header->flags |= IPFLAG_MORE_FRAGMENTS;
+			SET_HEADER_FLAGS(header,
+			    (GET_HEADER_FLAGS(header) | IPFLAG_MORE_FRAGMENTS));
 			middle_header->total_length =
 			    htons(packet_get_data_length(next));
-			middle_header->fragment_offset_high =
-			    IP_COMPUTE_FRAGMENT_OFFSET_HIGH(length);
+			SET_HEADER_FRAGMENT_OFFSET_HIGH(middle_header,
+			    IP_COMPUTE_FRAGMENT_OFFSET_HIGH(length));
 			middle_header->fragment_offset_low =
 			    IP_COMPUTE_FRAGMENT_OFFSET_LOW(length);
@@ -768,6 +769,6 @@
 		middle_header->total_length =
 		    htons(packet_get_data_length(next));
-		middle_header->fragment_offset_high =
-		    IP_COMPUTE_FRAGMENT_OFFSET_HIGH(length);
+		SET_HEADER_FRAGMENT_OFFSET_HIGH(middle_header,
+		    IP_COMPUTE_FRAGMENT_OFFSET_HIGH(length));
 		middle_header->fragment_offset_low =
 		    IP_COMPUTE_FRAGMENT_OFFSET_LOW(length);
@@ -785,5 +786,6 @@
 		length += packet_get_data_length(next);
 		free(last_header);
-		header->flags |= IPFLAG_MORE_FRAGMENTS;
+		SET_HEADER_FLAGS(header,
+		    (GET_HEADER_FLAGS(header) | IPFLAG_MORE_FRAGMENTS));
 	}
 
@@ -834,6 +836,6 @@
 	new_header->total_length = htons(IP_HEADER_LENGTH(new_header) + length);
 	offset = IP_FRAGMENT_OFFSET(header) + IP_HEADER_DATA_LENGTH(header);
-	new_header->fragment_offset_high =
-	    IP_COMPUTE_FRAGMENT_OFFSET_HIGH(offset);
+	SET_HEADER_FRAGMENT_OFFSET_HIGH(new_header,
+	    IP_COMPUTE_FRAGMENT_OFFSET_HIGH(offset));
 	new_header->fragment_offset_low =
 	    IP_COMPUTE_FRAGMENT_OFFSET_LOW(offset);
@@ -865,5 +867,6 @@
 		return NULL;
 	memcpy(middle, last, IP_HEADER_LENGTH(last));
-	middle->flags |= IPFLAG_MORE_FRAGMENTS;
+	SET_HEADER_FLAGS(middle,
+	    (GET_HEADER_FLAGS(middle) | IPFLAG_MORE_FRAGMENTS));
 	return middle;
 }
@@ -922,5 +925,5 @@
 
 	/* Fragmentation forbidden? */
-	if(header->flags & IPFLAG_DONT_FRAGMENT)
+	if(GET_HEADER_FLAGS(header) & IPFLAG_DONT_FRAGMENT)
 		return EPERM;
 
@@ -958,5 +961,6 @@
 
 	/* Mark the first as fragmented */
-	header->flags |= IPFLAG_MORE_FRAGMENTS;
+	SET_HEADER_FLAGS(header,
+	    (GET_HEADER_FLAGS(header) | IPFLAG_MORE_FRAGMENTS));
 
 	/* Create middle fragments */
@@ -1319,5 +1323,5 @@
 	int rc;
 
-	if ((header->flags & IPFLAG_MORE_FRAGMENTS) ||
+	if ((GET_HEADER_FLAGS(header) & IPFLAG_MORE_FRAGMENTS) ||
 	    IP_FRAGMENT_OFFSET(header)) {
 		// TODO fragmented
@@ -1325,5 +1329,5 @@
 	}
 	
-	switch (header->version) {
+	switch (GET_HEADER_VERSION(header)) {
 	case IPVERSION:
 		addrlen = sizeof(src_in);
@@ -1447,5 +1451,5 @@
 
 	/* Set the destination address */
-	switch (header->version) {
+	switch (GET_HEADER_VERSION(header)) {
 	case IPVERSION:
 		addrlen = sizeof(addr_in);