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| author | Arun Ajith S <aajith@arista.com> | 2022-04-15 11:34:02 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-04-17 15:23:49 +0300 |
| commit | f9a2fb73318eb4dbf8cd84866b8b0dd012d8b116 (patch) | |
| tree | 1441aad939fad8f1112d3bfb24eec862e472f0ee /Documentation/networking | |
| parent | 0339d25a2807d913f5645b8d5e485640915f9702 (diff) | |
| download | linux-f9a2fb73318eb4dbf8cd84866b8b0dd012d8b116.tar.xz | |
net/ipv6: Introduce accept_unsolicited_na knob to implement router-side changes for RFC9131
Add a new neighbour cache entry in STALE state for routers on receiving
an unsolicited (gratuitous) neighbour advertisement with
target link-layer-address option specified.
This is similar to the arp_accept configuration for IPv4.
A new sysctl endpoint is created to turn on this behaviour:
/proc/sys/net/ipv6/conf/interface/accept_unsolicited_na.
Signed-off-by: Arun Ajith S <aajith@arista.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/ip-sysctl.rst | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index b0024aa7b051..433f2e4a5fed 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -2467,6 +2467,33 @@ drop_unsolicited_na - BOOLEAN By default this is turned off. +accept_unsolicited_na - BOOLEAN + Add a new neighbour cache entry in STALE state for routers on receiving an + unsolicited neighbour advertisement with target link-layer address option + specified. This is as per router-side behavior documented in RFC9131. + This has lower precedence than drop_unsolicited_na. + + ==== ====== ====== ============================================== + drop accept fwding behaviour + ---- ------ ------ ---------------------------------------------- + 1 X X Drop NA packet and don't pass up the stack + 0 0 X Pass NA packet up the stack, don't update NC + 0 1 0 Pass NA packet up the stack, don't update NC + 0 1 1 Pass NA packet up the stack, and add a STALE + NC entry + ==== ====== ====== ============================================== + + 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. + enhanced_dad - BOOLEAN Include a nonce option in the IPv6 neighbor solicitation messages used for duplicate address detection per RFC7527. A received DAD NS will only signal |