patch-2.4.26 linux-2.4.26/Documentation/networking/ip-sysctl.txt

• Lines: 56
• Date: 2004-04-14 06:05:25.000000000 -0700
• Orig file: linux-2.4.25/Documentation/networking/ip-sysctl.txt
• Orig date: 2003-06-13 07:51:29.000000000 -0700

diff -urN linux-2.4.25/Documentation/networking/ip-sysctl.txt linux-2.4.26/Documentation/networking/ip-sysctl.txt
@@ -481,6 +481,55 @@
 	conf/{all,interface}/arp_filter is set to TRUE,
 	it will be disabled otherwise
 
+arp_announce - INTEGER
+	Define different restriction levels for announcing the local
+	source IP address from IP packets in ARP requests sent on
+	interface:
+	0 - (default) Use any local address, configured on any interface
+	1 - Try to avoid local addresses that are not in the target's
+	subnet for this interface. This mode is useful when target
+	hosts reachable via this interface require the source IP
+	address in ARP requests to be part of their logical network
+	configured on the receiving interface. When we generate the
+	request we will check all our subnets that include the
+	target IP and will preserve the source address if it is from
+	such subnet. If there is no such subnet we select source
+	address according to the rules for level 2.
+	2 - Always use the best local address for this target.
+	In this mode we ignore the source address in the IP packet
+	and try to select local address that we prefer for talks with
+	the target host. Such local address is selected by looking
+	for primary IP addresses on all our subnets on the outgoing
+	interface that include the target IP address. If no suitable
+	local address is found we select the first local address
+	we have on the outgoing interface or on all other interfaces,
+	with the hope we will receive reply for our request and
+	even sometimes no matter the source IP address we announce.
+
+	The max value from conf/{all,interface}/arp_announce is used.
+
+	Increasing the restriction level gives more chance for
+	receiving answer from the resolved target while decreasing
+	the level announces more valid sender's information.
+
+arp_ignore - INTEGER
+	Define different modes for sending replies in response to
+	received ARP requests that resolve local target IP addresses:
+	0 - (default): reply for any local target IP address, configured
+	on any interface
+	1 - reply only if the target IP address is local address
+	configured on the incoming interface
+	2 - reply only if the target IP address is local address
+	configured on the incoming interface and both with the
+	sender's IP address are part from same subnet on this interface
+	3 - do not reply for local addresses configured with scope host,
+	only resolutions for global and link addresses are replied
+	4-7 - reserved
+	8 - do not reply for all local addresses
+
+	The max value from conf/{all,interface}/arp_ignore is used
+	when ARP request is received on the {interface}
+
 tag - INTEGER
 	Allows you to write a number, which can be used as required.
 	Default value is 0.