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authorJaehee Park <jhpark1013@gmail.com>2022-07-13 16:40:47 -0700
committerJakub Kicinski <kuba@kernel.org>2022-07-15 18:55:49 -0700
commite68c5dcf0aacc48a23cedcb3ce81b8c60837f48c (patch)
treec89fddb75cef6e3d2e2159417e6e4ab9492a03ca /Documentation/networking
parent459f326e995ce6f02f3dc79ca5bc4e2abe33d156 (diff)
net: ipv4: new arp_accept option to accept garp only if in-network
In many deployments, we want the option to not learn a neighbor from garp if the src ip is not in the same subnet as an address configured on the interface that received the garp message. net.ipv4.arp_accept sysctl is currently used to control creation of a neigh from a received garp packet. This patch adds a new option '2' to net.ipv4.arp_accept which extends option '1' by including the subnet check. Signed-off-by: Jaehee Park <jhpark1013@gmail.com> Suggested-by: Roopa Prabhu <roopa@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/ip-sysctl.rst9
1 files changed, 6 insertions, 3 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 2b329042b38c..b31601405c54 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1633,12 +1633,15 @@ arp_notify - BOOLEAN
or hardware address changes.
== ==========================================================
-arp_accept - BOOLEAN
- Define behavior for gratuitous ARP frames who's IP is not
- already present in the ARP table:
+arp_accept - INTEGER
+ Define behavior for accepting gratuitous ARP (garp) frames from devices
+ that are not already present in the ARP table:
- 0 - don't create new entries in the ARP table
- 1 - create new entries in the ARP table
+ - 2 - create new entries only if the source IP address is in the same
+ subnet as an address configured on the interface that received the
+ garp message.
Both replies and requests type gratuitous arp will trigger the
ARP table to be updated, if this setting is on.