diff -urNb src/sbin/ifconfig/ifconfig.c src-proxyarp/sbin/ifconfig/ifconfig.c
--- src/sbin/ifconfig/ifconfig.c	2006-03-19 02:59:22.000000000 +0500
+++ src-proxyarp/sbin/ifconfig/ifconfig.c	2007-08-21 21:40:26.000000000 +0600
@@ -812,7 +812,7 @@
 #define	IFFBITS \
 "\020\1UP\2BROADCAST\3DEBUG\4LOOPBACK\5POINTOPOINT\6SMART\7RUNNING" \
 "\10NOARP\11PROMISC\12ALLMULTI\13OACTIVE\14SIMPLEX\15LINK0\16LINK1\17LINK2" \
-"\20MULTICAST\22PPROMISC\23MONITOR\24STATICARP\25NEEDSGIANT"
+"\20MULTICAST\22PPROMISC\23MONITOR\24STATICARP\25NEEDSGIANT\26PROXYARP"
 
 #define	IFCAPBITS \
 "\020\1RXCSUM\2TXCSUM\3NETCONS\4VLAN_MTU\5VLAN_HWTAGGING\6JUMBO_MTU\7POLLING"
@@ -1050,6 +1050,8 @@
 	DEF_CMD("noicmp",	IFF_LINK1,	setifflags),
 	DEF_CMD_ARG("mtu",			setifmtu),
 	DEF_CMD_ARG("name",			setifname),
+	DEF_CMD("proxyarp",	IFF_PROXYARP,	setifflags),
+	DEF_CMD("-proxyarp",	-IFF_PROXYARP,	setifflags),
 };
 
 static __constructor void
diff -urNb src/sys/net/if.h src-proxyarp/sys/net/if.h
--- src/sys/net/if.h	2006-02-15 08:37:15.000000000 +0500
+++ src-proxyarp/sys/net/if.h	2007-08-21 21:40:26.000000000 +0600
@@ -153,6 +153,7 @@
 #define	IFF_MONITOR	0x40000		/* (n) user-requested monitor mode */
 #define	IFF_STATICARP	0x80000		/* (n) static ARP */
 #define	IFF_NEEDSGIANT	0x100000	/* (i) hold Giant over if_start calls */
+#define	IFF_PROXYARP	0x200000	/* (n) enable "local-proxy-arp" mode */
 
 /*
  * Old names for driver flags so that user space tools can continue to use
diff -urNb src/sys/netinet/if_ether.c src-proxyarp/sys/netinet/if_ether.c
--- src/sys/netinet/if_ether.c	2007-03-14 02:59:20.000000000 +0500
+++ src-proxyarp/sys/netinet/if_ether.c	2007-08-22 01:23:19.000000000 +0600
@@ -105,6 +105,7 @@
 static int	arp_maxtries = 5;
 static int	useloopback = 1; /* use loopback interface for local traffic */
 static int	arp_proxyall = 0;
+static int	localproxyarp_delay = 0;
 static struct callout arp_callout;
 
 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
@@ -113,6 +114,8 @@
 	   &useloopback, 0, "");
 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
 	   &arp_proxyall, 0, "");
+SYSCTL_INT(_net_link_ether_inet, OID_AUTO, local_proxyarp_delay, CTLFLAG_RW,
+	   &localproxyarp_delay, 0, "Local Proxy ARP delay (microseconds), may help to win the race");
 
 static void	arp_init(void);
 static void	arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
@@ -814,7 +817,7 @@
 		if (rt == NULL) {
 			struct sockaddr_in sin;
 
-			if (!arp_proxyall)
+			if (!arp_proxyall && !(ifp->if_flags & IFF_PROXYARP))
 				goto drop;
 
 			bzero(&sin, sizeof sin);
@@ -830,10 +833,26 @@
 			 * as this one came out of, or we'll get into a fight
 			 * over who claims what Ether address.
 			 */
-			if (rt->rt_ifp == ifp) {
+			if ((rt->rt_ifp == ifp) && \
+				!(ifp->if_flags & IFF_PROXYARP)) {
 				rtfree(rt);
 				goto drop;
 			}
+
+			/*
+			 * PROXYARP: Windows workaround
+			 */
+
+			if ((ifp->if_flags & IFF_PROXYARP) && \
+				(isaddr.s_addr == itaddr.s_addr)) {
+				rtfree(rt);
+				goto drop;
+			}
+
+			/* PROXYARP: Delay sending reply for specified time */
+			if (ifp->if_flags & IFF_PROXYARP)
+				DELAY(localproxyarp_delay);
+
 			(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
 			(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
 			rtfree(rt);