diff --git a/sys/net/bpf.h b/sys/net/bpf.h
index ccea1ea78c69..4714ffb5a0bc 100644
--- a/sys/net/bpf.h
+++ b/sys/net/bpf.h
@@ -37,9 +37,12 @@
  *
  *      @(#)bpf.h	8.1 (Berkeley) 6/10/93
  *
- * $Id$
+ * $Id: bpf.h,v 1.2 1994/08/02 07:45:54 davidg Exp $
  */
 
+#ifndef _NET_BPF_H_
+#define _NET_BPF_H_
+
 /*
  * Alignment macros.  BPF_WORDALIGN rounds up to the next 
  * even multiple of BPF_ALIGNMENT. 
@@ -250,3 +253,4 @@ u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
  */
 #define BPF_MEMWORDS 16
 
+#endif
diff --git a/sys/net/bpf_compat.h b/sys/net/bpf_compat.h
index 682426c96639..44dab52e0c9d 100644
--- a/sys/net/bpf_compat.h
+++ b/sys/net/bpf_compat.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)bpf_compat.h	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: bpf_compat.h,v 1.2 1994/08/02 07:45:56 davidg Exp $
  */
 
+#ifndef _NET_BPF_COMPAT_H_
+#define _NET_BPF_COMPAT_H_
+
 /*
  * Some hacks for compatibility across SunOS and 4.4BSD.  We emulate malloc
  * and free with mbuf clusters.  We store a pointer to the mbuf in the first
@@ -47,3 +50,5 @@
 
 /* This mapping works for our purposes. */
 #define ERESTART EINTR
+
+#endif
diff --git a/sys/net/bpfdesc.h b/sys/net/bpfdesc.h
index fbcc3ffe448c..598ce9e2337c 100644
--- a/sys/net/bpfdesc.h
+++ b/sys/net/bpfdesc.h
@@ -37,9 +37,12 @@
  *
  *      @(#)bpfdesc.h	8.1 (Berkeley) 6/10/93
  *
- * $Id$
+ * $Id: bpfdesc.h,v 1.3 1994/08/02 07:46:00 davidg Exp $
  */
 
+#ifndef _NET_BPFDESC_H_
+#define _NET_BPFDESC_H_
+
 #include <sys/select.h>
 
 /*
@@ -98,3 +101,5 @@ struct bpf_if {
 #ifdef KERNEL
 int	 bpf_setf __P((struct bpf_d *, struct bpf_program *));
 #endif
+
+#endif
diff --git a/sys/net/if.h b/sys/net/if.h
index 3b1e6d83f8ab..d91d92f2a8fb 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)if.h	8.1 (Berkeley) 6/10/93
- * $Id: if.h,v 1.4 1994/08/08 10:49:19 davidg Exp $
+ * $Id: if.h,v 1.5 1994/08/18 22:35:20 wollman Exp $
  */
 
+#ifndef _NET_IF_H_
+#define _NET_IF_H_
+
 /*
  * Structures defining a network interface, providing a packet
  * transport mechanism (ala level 0 of the PUP protocols).
@@ -364,3 +367,5 @@ int	looutput __P((struct ifnet *,
 	   struct mbuf *, struct sockaddr *, struct rtentry *));
 void	lortrequest __P((int, struct rtentry *, struct sockaddr *));
 #endif
+
+#endif
diff --git a/sys/net/if_arp.h b/sys/net/if_arp.h
index 9642ddfbbf1b..471e2e0ce267 100644
--- a/sys/net/if_arp.h
+++ b/sys/net/if_arp.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)if_arp.h	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: if_arp.h,v 1.2 1994/08/02 07:46:10 davidg Exp $
  */
 
+#ifndef _NET_IF_ARP_H_
+#define _NET_IF_ARP_H_
+
 /*
  * Address Resolution Protocol.
  *
@@ -84,3 +87,5 @@ struct arpreq {
 #define	ATF_PERM	0x04	/* permanent entry */
 #define	ATF_PUBL	0x08	/* publish entry (respond for other host) */
 #define	ATF_USETRAILERS	0x10	/* has requested trailers */
+
+#endif
diff --git a/sys/net/if_dl.h b/sys/net/if_dl.h
index d08f393d53eb..f3db94a0eb2b 100644
--- a/sys/net/if_dl.h
+++ b/sys/net/if_dl.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)if_dl.h	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: if_dl.h,v 1.2 1994/08/02 07:46:12 davidg Exp $
  */
 
+#ifndef _NET_IF_DL_H_
+#define _NET_IF_DL_H_
+
 /* 
  * A Link-Level Sockaddr may specify the interface in one of two
  * ways: either by means of a system-provided index number (computed
@@ -79,3 +82,5 @@ char	*link_ntoa __P((const struct sockaddr_dl *));
 __END_DECLS
 
 #endif /* !KERNEL */
+
+#endif
diff --git a/sys/net/if_llc.h b/sys/net/if_llc.h
index b5793daa6374..da89ee7126f7 100644
--- a/sys/net/if_llc.h
+++ b/sys/net/if_llc.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *      @(#)if_llc.h	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: if_llc.h,v 1.2 1994/08/02 07:46:16 davidg Exp $
  */
 
+#ifndef _NET_IF_LLC_H_
+#define _NET_IF_LLC_H_
+
 /*
  * IEEE 802.2 Link Level Control headers, for use in conjunction with
  * 802.{3,4,5} media access control methods.
@@ -139,8 +142,4 @@ struct llc {
 #define LLC_SNAP_LSAP	0xaa
 #define LLC_ISO_LSAP	0xfe
 
-
-
-
-
-
+#endif
diff --git a/sys/net/if_slvar.h b/sys/net/if_slvar.h
index b3626f3c6679..a7926a7a2336 100644
--- a/sys/net/if_slvar.h
+++ b/sys/net/if_slvar.h
@@ -32,9 +32,12 @@
  *
  *	@(#)if_slvar.h	8.3 (Berkeley) 2/1/94
  *
- * $Id$
+ * $Id: if_slvar.h,v 1.2 1994/08/02 07:46:22 davidg Exp $
  */
 
+#ifndef _NET_IF_SLVAR_H_
+#define _NET_IF_SLVAR_H_
+
 /*
  * Definitions for SLIP interface data structures
  * 
@@ -78,3 +81,5 @@ int	sloutput __P((struct ifnet *,
 void	slstart __P((struct tty *));
 int	sltioctl __P((struct tty *, int, caddr_t, int));
 #endif /* KERNEL */
+
+#endif
diff --git a/sys/net/if_types.h b/sys/net/if_types.h
index 3f1b59ea3fc3..cb0dff1b3f41 100644
--- a/sys/net/if_types.h
+++ b/sys/net/if_types.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)if_types.h	8.2 (Berkeley) 4/20/94
- * $Id$
+ * $Id: if_types.h,v 1.2 1994/08/02 07:46:26 davidg Exp $
  */
 
+#ifndef _NET_IF_TYPES_H_
+#define _NET_IF_TYPES_H_
+
 /*
  * Interface types for benefit of parsing media address headers.
  * This list is derived from the SNMP list of ifTypes, currently
@@ -94,3 +97,5 @@
 #define	IFT_SMDSICIP	0x34		/* SMDS InterCarrier Interface */
 #define	IFT_PROPVIRTUAL	0x35		/* Proprietary Virtual/internal */
 #define	IFT_PROPMUX	0x36		/* Proprietary Multiplexing */
+
+#endif
diff --git a/sys/net/netisr.h b/sys/net/netisr.h
index 48bec1c37e4d..1a4b3f482422 100644
--- a/sys/net/netisr.h
+++ b/sys/net/netisr.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)netisr.h	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: netisr.h,v 1.3 1994/08/02 07:46:27 davidg Exp $
  */
 
+#ifndef _NET_NETISR_H_
+#define _NET_NETISR_H_
+
 /*
  * The networking code runs off software interrupts.
  *
@@ -67,3 +70,5 @@
 volatile unsigned int	netisr;				/* scheduling bits for network */
 #endif
 #endif
+
+#endif
diff --git a/sys/net/radix.h b/sys/net/radix.h
index 1f79cd5caec9..29099243d52e 100644
--- a/sys/net/radix.h
+++ b/sys/net/radix.h
@@ -31,11 +31,11 @@
  * SUCH DAMAGE.
  *
  *	@(#)radix.h	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: radix.h,v 1.2 1994/08/02 07:46:31 davidg Exp $
  */
 
-#ifndef _RADIX_H_
-#define	_RADIX_H_
+#ifndef _NET_RADIX_H_
+#define	_NET_RADIX_H_
 
 /*
  * Radix search tree node layout.
diff --git a/sys/net/raw_cb.h b/sys/net/raw_cb.h
index 65b3621e92f8..e975432e2180 100644
--- a/sys/net/raw_cb.h
+++ b/sys/net/raw_cb.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)raw_cb.h	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: raw_cb.h,v 1.2 1994/08/02 07:46:36 davidg Exp $
  */
 
+#ifndef _NET_RAW_CB_H_
+#define _NET_RAW_CB_H_
+
 /*
  * Raw protocol interface control block.  Used
  * to tie a socket to the generic raw interface.
@@ -68,3 +71,5 @@ void	 raw_input __P((struct mbuf *,
 int	 raw_usrreq __P((struct socket *,
 	    int, struct mbuf *, struct mbuf *, struct mbuf *));
 #endif
+
+#endif
diff --git a/sys/net/route.h b/sys/net/route.h
index e9c387395c6f..9812945d3e15 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)route.h	8.3 (Berkeley) 4/19/94
- * $Id$
+ * $Id: route.h,v 1.3 1994/08/02 07:46:42 davidg Exp $
  */
 
+#ifndef _NET_ROUTE_H_
+#define _NET_ROUTE_H_
+
 /*
  * Kernel resident routing tables.
  * 
@@ -260,3 +263,5 @@ void	 rtredirect __P((struct sockaddr *, struct sockaddr *,
 int	 rtrequest __P((int, struct sockaddr *,
 	    struct sockaddr *, struct sockaddr *, int, struct rtentry **));
 #endif
+
+#endif
diff --git a/sys/net/slcompress.h b/sys/net/slcompress.h
index 6df5fa6443fa..be43d65dc09b 100644
--- a/sys/net/slcompress.h
+++ b/sys/net/slcompress.h
@@ -35,9 +35,12 @@
  *
  *	Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
  *	- Initial distribution.
- * $Id$
+ * $Id: slcompress.h,v 1.2 1994/08/02 07:46:48 davidg Exp $
  */
 
+#define _NET_SLCOMPRESS_H_
+#define _NET_SLCOMPRESS_H_
+
 #define MAX_STATES 16		/* must be > 2 and < 256 */
 #define MAX_HDR MLEN		/* XXX 4bsd-ism: should really be 128 */
 
@@ -153,4 +156,6 @@ struct slcompress {
 void	 sl_compress_init __P((struct slcompress *));
 u_int	 sl_compress_tcp __P((struct mbuf *,
 	    struct ip *, struct slcompress *, int));
+
+#endif
 int	 sl_uncompress_tcp __P((u_char **, int, u_int, struct slcompress *));
diff --git a/sys/net/slip.h b/sys/net/slip.h
index 52ecfed60365..1c9ffca90677 100644
--- a/sys/net/slip.h
+++ b/sys/net/slip.h
@@ -31,9 +31,12 @@
  * SUCH DAMAGE.
  *
  *	@(#)slip.h	8.1 (Berkeley) 2/12/94
- * $Id$
+ * $Id: slip.h,v 1.2 1994/08/02 07:46:50 davidg Exp $
  */
 
+#ifndef _NET_SLIP_H_
+#define _NET_SLIP_H_
+
 /* Ioctls operating on SLIP ttys. */
 #define	SLIOCGUNIT	_IOR('t', 88, int)	/* get slip unit number */
 
@@ -49,4 +52,6 @@
 #define	CHDR_LEN	15		/* length of compressed header data */
 
 #define	SLIPDIR_IN	0		/* incoming */
+
+#endif
 #define	SLIPDIR_OUT	1		/* outgoing */