vpp-manager: disable punting NAs toward the host#940
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This patch prevents neighbor advertisements from being punted toward the host. The expectation is that linux will issue NS that will hit NDproxy, thus we should consume NAs in VPP, and learn neighbors, but not transmit the packets to linux. This is especially useful in the case where we loose the node IP (e.g. when dhcpv6 lease renewal fails), as forwarding NAs destined to the nodeIP to linux with a default route towards VPP will result in VPP learning neighbors on the tap0 instead of the uplink. We also include an evolution in ND proxy that removes the need to allowlist destination IPs that VPP will reply to. That way we can have the guarantee that all next hops in linux will be the MAC address of the Gateway, regardless of the routing on the node. Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
aritrbas
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Mar 11, 2026
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This patch prevents neighbor advertisements from being punted toward the host. The expectation is that linux will issue NS that will hit NDproxy, thus we should consume NAs in VPP, and learn neighbors, but not transmit the packets to linux.
This is especially useful in the case where we loose the node IP (e.g. when dhcpv6 lease renewal fails), as forwarding NAs destined to the nodeIP to linux with a default route towards VPP will result in VPP learning neighbors on the tap0 instead of the uplink.
We also include an evolution in ND proxy that removes the need
to allowlist destination IPs that VPP will reply to. That way
we can have the guarantee that all next hops in linux will
be the MAC address of the Gateway, regardless of the routing
on the node.