Confirm neighbor reachability with TCP ACKs
As per RFC 4861 section 7.3.1,
A neighbor is considered reachable if the node has recently received
a confirmation that packets sent recently to the neighbor were
received by its IP layer. Positive confirmation can be gathered in
two ways: hints from upper-layer protocols that indicate a connection
is making "forward progress", or receipt of a Neighbor Advertisement
message that is a response to a Neighbor Solicitation message.
This change adds support for TCP to let the IP/link layers know that a
neighbor is reachable.
Test: integration_test.TestTCPConfirmNeighborReachability
PiperOrigin-RevId: 354222833
This is a cherry pick of 3fed82e.
Bug: 70276
Change-Id: I50c74a8e14424d653b714c6a8f7968d71fe98f3d
6 files changed
