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authorJaehee Park <jhpark1013@gmail.com>2022-07-14 02:40:48 +0300
committerJakub Kicinski <kuba@kernel.org>2022-07-16 04:55:50 +0300
commitaaa5f515b16b6b3e137779ffb4c9558bb58c1e75 (patch)
treeed38a6a92803ee96890a6e3661450511019d5859 /Documentation/networking
parente68c5dcf0aacc48a23cedcb3ce81b8c60837f48c (diff)
downloadlinux-aaa5f515b16b6b3e137779ffb4c9558bb58c1e75.tar.xz
net: ipv6: new accept_untracked_na option to accept na only if in-network
This patch adds a third knob, '2', which extends the accept_untracked_na option to learn a neighbor only if the src ip is in the same subnet as an address configured on the interface that received the neighbor advertisement. This is similar to the arp_accept configuration for ipv4. 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.rst51
1 files changed, 30 insertions, 21 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index b31601405c54..1c3897a4e60f 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -2483,27 +2483,36 @@ drop_unsolicited_na - BOOLEAN
By default this is turned off.
-accept_untracked_na - BOOLEAN
- Add a new neighbour cache entry in STALE state for routers on receiving a
- neighbour advertisement (either solicited or unsolicited) with target
- link-layer address option specified if no neighbour entry is already
- present for the advertised IPv6 address. Without this knob, NAs received
- for untracked addresses (absent in neighbour cache) are silently ignored.
-
- This is as per router-side behaviour documented in RFC9131.
-
- This has lower precedence than drop_unsolicited_na.
-
- This will optimize the return path for the initial off-link communication
- that is initiated by a directly connected host, by ensuring that
- the first-hop router which turns on this setting doesn't have to
- buffer the initial return packets to do neighbour-solicitation.
- The prerequisite is that the host is configured to send
- unsolicited neighbour advertisements on interface bringup.
- This setting should be used in conjunction with the ndisc_notify setting
- on the host to satisfy this prerequisite.
-
- By default this is turned off.
+accept_untracked_na - INTEGER
+ Define behavior for accepting neighbor advertisements from devices that
+ are absent in the neighbor cache:
+
+ - 0 - (default) Do not accept unsolicited and untracked neighbor
+ advertisements.
+
+ - 1 - Add a new neighbor cache entry in STALE state for routers on
+ receiving a neighbor advertisement (either solicited or unsolicited)
+ with target link-layer address option specified if no neighbor entry
+ is already present for the advertised IPv6 address. Without this knob,
+ NAs received for untracked addresses (absent in neighbor cache) are
+ silently ignored.
+
+ This is as per router-side behavior documented in RFC9131.
+
+ This has lower precedence than drop_unsolicited_na.
+
+ This will optimize the return path for the initial off-link
+ communication that is initiated by a directly connected host, by
+ ensuring that the first-hop router which turns on this setting doesn't
+ have to buffer the initial return packets to do neighbor-solicitation.
+ The prerequisite is that the host is configured to send unsolicited
+ neighbor advertisements on interface bringup. This setting should be
+ used in conjunction with the ndisc_notify setting on the host to
+ satisfy this prerequisite.
+
+ - 2 - Extend option (1) to add a new neighbor cache entry only if the
+ source IP address is in the same subnet as an address configured on
+ the interface that received the neighbor advertisement.
enhanced_dad - BOOLEAN
Include a nonce option in the IPv6 neighbor solicitation messages used for