diff -urp v2.6.36/linux/Documentation/networking/ip-sysctl.txt linux/Documentation/networking/ip-sysctl.txt
--- v2.6.36/linux/Documentation/networking/ip-sysctl.txt	2010-10-22 11:34:27.000000000 +0300
+++ linux/Documentation/networking/ip-sysctl.txt	2010-10-22 11:42:40.237176553 +0300
@@ -933,6 +933,14 @@ disable_xfrm - BOOLEAN
 
 
 
+hidden - BOOLEAN
+	Hide addresses attached to this device from other devices.
+	Such addresses will never be selected by source address autoselection
+	mechanism, host does not answer broadcast ARP requests for them,
+	does not announce them as source address of ARP requests, but they
+	are still reachable via IP. This flag is activated only if it is
+	enabled both in specific device section and in "all" section.
+
 tag - INTEGER
 	Allows you to write a number, which can be used as required.
 	Default value is 0.
diff -urp v2.6.36/linux/include/linux/inetdevice.h linux/include/linux/inetdevice.h
--- v2.6.36/linux/include/linux/inetdevice.h	2010-05-17 10:49:00.000000000 +0300
+++ linux/include/linux/inetdevice.h	2010-10-22 11:42:40.237176553 +0300
@@ -31,6 +31,7 @@ enum
 	IPV4_DEVCONF_FORCE_IGMP_VERSION,
 	IPV4_DEVCONF_ARP_ANNOUNCE,
 	IPV4_DEVCONF_ARP_IGNORE,
+	IPV4_DEVCONF_HIDDEN,
 	IPV4_DEVCONF_PROMOTE_SECONDARIES,
 	IPV4_DEVCONF_ARP_ACCEPT,
 	IPV4_DEVCONF_ARP_NOTIFY,
@@ -126,6 +127,7 @@ static inline void ipv4_devconf_setall(s
 						      SECURE_REDIRECTS)
 #define IN_DEV_IDTAG(in_dev)		IN_DEV_CONF_GET(in_dev, TAG)
 #define IN_DEV_MEDIUM_ID(in_dev)	IN_DEV_CONF_GET(in_dev, MEDIUM_ID)
+#define IN_DEV_HIDDEN(in_dev)		IN_DEV_ANDCONF((in_dev), HIDDEN)
 #define IN_DEV_PROMOTE_SECONDARIES(in_dev) \
 					IN_DEV_ORCONF((in_dev), \
 						      PROMOTE_SECONDARIES)
diff -urp v2.6.36/linux/net/ipv4/arp.c linux/net/ipv4/arp.c
--- v2.6.36/linux/net/ipv4/arp.c	2010-10-22 11:34:38.000000000 +0300
+++ linux/net/ipv4/arp.c	2010-10-23 12:48:20.946274306 +0300
@@ -71,6 +71,8 @@
  *					sending (e.g. insert 8021q tag).
  *		Harald Welte	:	convert to make use of jenkins hash
  *		Jesper D. Brouer:       Proxy ARP PVLAN RFC 3069 support.
+ *		Julian Anastasov:	"hidden" flag: hide the
+ *					interface and don't reply for it
  */
 
 #include <linux/module.h>
@@ -336,7 +338,9 @@ static void arp_solicit(struct neighbour
 	struct net_device *dev = neigh->dev;
 	__be32 target = *(__be32*)neigh->primary_key;
 	int probes = atomic_read(&neigh->probes);
-	struct in_device *in_dev;
+	struct in_device *in_dev, *in_dev2;
+	struct net_device *dev2 = NULL;
+	int mode;
 
 	rcu_read_lock();
 	in_dev = __in_dev_get_rcu(dev);
@@ -344,17 +348,30 @@ static void arp_solicit(struct neighbour
 		rcu_read_unlock();
 		return;
 	}
-	switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
+	mode = IN_DEV_ARP_ANNOUNCE(in_dev);
+	if (mode != 2 && skb &&
+	    (dev2 = ip_dev_find(dev_net(dev), ip_hdr(skb)->saddr)) != NULL &&
+	    (saddr = ip_hdr(skb)->saddr,
+	     in_dev2 = __in_dev_get_rcu(dev2)) != NULL &&
+	    IN_DEV_HIDDEN(in_dev2)) {
+		saddr = 0;
+		goto get;
+	}
+
+	switch (mode) {
 	default:
 	case 0:		/* By default announce any local IP */
+		if (saddr)
+			break;
 		if (skb && inet_addr_type(dev_net(dev), ip_hdr(skb)->saddr) == RTN_LOCAL)
 			saddr = ip_hdr(skb)->saddr;
 		break;
 	case 1:		/* Restrict announcements of saddr in same subnet */
 		if (!skb)
 			break;
-		saddr = ip_hdr(skb)->saddr;
-		if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) {
+		if (saddr ||
+		    (saddr = ip_hdr(skb)->saddr,
+		     inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL)) {
 			/* saddr should be known to target */
 			if (inet_addr_onlink(in_dev, target, saddr))
 				break;
@@ -364,6 +381,10 @@ static void arp_solicit(struct neighbour
 	case 2:		/* Avoid secondary IPs, get a primary/preferred one */
 		break;
 	}
+
+get:
+	if (dev2)
+		dev_put(dev2);
 	rcu_read_unlock();
 
 	if (!saddr)
@@ -440,6 +461,23 @@ static int arp_filter(__be32 sip, __be32
 	return flag;
 }
 
+static int arp_hidden(u32 tip, struct net_device *dev)
+{
+	struct net_device *dev2 = NULL;
+	struct in_device *in_dev2;
+	int ret = 0;
+
+	if (!IPV4_DEVCONF_ALL(dev_net(dev), HIDDEN))
+		return 0;
+
+	if ((dev2 = ip_dev_find(dev_net(dev), tip)) && dev2 != dev &&
+	    (in_dev2 = __in_dev_get_rcu(dev2)) && IN_DEV_HIDDEN(in_dev2))
+		ret = 1;
+	if (dev2)
+		dev_put(dev2);
+	return ret;
+}
+
 /* OBSOLETE FUNCTIONS */
 
 /*
@@ -856,6 +894,7 @@ static int arp_process(struct sk_buff *s
 	if (sip == 0) {
 		if (arp->ar_op == htons(ARPOP_REQUEST) &&
 		    inet_addr_type(net, tip) == RTN_LOCAL &&
+		    !arp_hidden(tip, dev) &&
 		    !arp_ignore(in_dev, sip, tip))
 			arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
 				 dev->dev_addr, sha);
@@ -875,6 +914,8 @@ static int arp_process(struct sk_buff *s
 				dont_send |= arp_ignore(in_dev,sip,tip);
 			if (!dont_send && IN_DEV_ARPFILTER(in_dev))
 				dont_send |= arp_filter(sip,tip,dev);
+			if (!dont_send && skb->pkt_type != PACKET_HOST)
+				dont_send |= arp_hidden(tip,dev); 
 			if (!dont_send) {
 				n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
 				if (n) {
diff -urp v2.6.36/linux/net/ipv4/devinet.c linux/net/ipv4/devinet.c
--- v2.6.36/linux/net/ipv4/devinet.c	2010-10-22 11:34:38.000000000 +0300
+++ linux/net/ipv4/devinet.c	2010-10-22 11:42:40.247176832 +0300
@@ -897,7 +897,8 @@ no_in_dev:
 			continue;
 
 		for_primary_ifa(in_dev) {
-			if (ifa->ifa_scope != RT_SCOPE_LINK &&
+			if (!IN_DEV_HIDDEN(in_dev) &&
+			    ifa->ifa_scope != RT_SCOPE_LINK &&
 			    ifa->ifa_scope <= scope) {
 				addr = ifa->ifa_local;
 				goto out_unlock;
@@ -1410,6 +1411,7 @@ static struct devinet_sysctl_table {
 		DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
 		DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
 		DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
+		DEVINET_SYSCTL_RW_ENTRY(HIDDEN, "hidden"),
 		DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
 		DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
 		DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),