| // Copyright 2019 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| library fuchsia.net.neighbor; |
| |
| /// Neighbor table entry state. |
| /// |
| /// Modeled after RFC 4861 section 7.3.2. Descriptions are kept |
| /// implementation-independent by using a set of generic terminology. |
| /// |
| /// ,------------------------------------------------------------------. |
| /// | Generic Term | ARP Term | NDP Term | |
| /// |---------------------------+-------------+------------------------| |
| /// | Reachability Probe | ARP Request | Neighbor Solicitation | |
| /// | Reachability Confirmation | ARP Reply | Neighbor Advertisement | |
| /// `---------------------------+-------------+------------------------' |
| type EntryState = strict enum : uint8 { |
| /// Reachability is in the process of being confirmed for a newly created, |
| /// non-static entry. |
| INCOMPLETE = 1; |
| |
| /// Positive reachability has been confirmed; the path to the neighbor is |
| /// functioning properly. |
| REACHABLE = 2; |
| |
| /// Reachability is considered unknown. |
| /// |
| /// Occurs in one of two ways: |
| /// 1. Too much time has elapsed since the last positive reachability |
| /// confirmation was received. |
| /// 2. Received a reachability confirmation from a neighbor with a |
| /// different MAC address than the one cached. |
| STALE = 3; |
| |
| /// A packet was recently sent while reachability was considered unknown. |
| /// |
| /// This state is an optimization that gives non-Neighbor-Discovery related |
| /// protocols time to confirm reachability after the last confirmation of |
| /// reachability has expired due to lack of recent traffic. |
| DELAY = 4; |
| |
| /// A reachability confirmation is actively sought by periodically |
| /// retransmitting reachability probes until a reachability confirmation is |
| /// received, or until the maximum number of probes has been sent. |
| PROBE = 5; |
| |
| /// Static entries are explicitly added with [`Controller.AddEntry`]. They |
| /// do not expire and are not deleted until explicitly removed with |
| /// [`Controller.RemoveEntry`]. |
| STATIC = 6; |
| |
| /// Negative reachability has been confirmed; the path to the neighbor may |
| /// not be functioning properly. A reachability confirmation was not received |
| /// after transmitting the maximum number of reachability probes. |
| UNREACHABLE = 7; |
| }; |