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mpath
# iw dev mesh mpath dump
00:ff:f3:a0:24:bd 00:ff:f3:00:fe:25 mesh 51 25507 0 3341812736 100 0 0x4
00:ff:f3:00:fe:25 00:ff:f3:00:fe:25 mesh 7 8577 0 3341812736 0 0 0x10
00:ff:f3:a0:24:54 00:ff:f3:a0:24:54 mesh 0 14049 0 3341812736 0 0 0x10
The columns, from left to right, are:
The destination for this Mesh Path. Direct paths have the same MAC address for the destination and next-hop.
The next hop on the way to the destination. Direct paths have the same MAC address for the destination and next-hop.
Network device (ex: "mesh").
The Destination Sequence Number for this path. The DSN is used to determine the 'freshnesss' of a node's path information. For example, suppose a node receives a path response for a destination that is already in its path table. If the path response has a higher DSN, it will replace the existing path because it will be considered fresher.
A metric (or "cost") of taking the path. Lower metrics are preferred and, given the choice of multiple paths, the stack will chose the least expensive (ie: the one with the lowest Air Time Link Metric).
The value is derived using the expected throughput (metric = 1 + 8192 / expected_throughput_mbps). Expected Throughput mbps is driver depended (e.g. some include retransmissions). More details can be found in airtime_link_metric_get at net/mac80211/mesh_hwmp.c.
IEEE P802.11-REVmc/D6.0, June 2016 section 14.9 states:
Airtime reflects the amount of channel resources consumed by transmitting the frame over a particular link. This measure is approximate and designed for ease of implementation and interoperability.
Number of queued frames for this Mesh Path.
Time when this Mesh Path will expire, in jiffies.
Time remaining for path discovery (if this path is being discovered).
Number of times discovery has been retried (if this path is being discovered).
This is a bitmask consisting of the following state flags for this path:
MESH_PATH_ACTIVE = BIT(0),
MESH_PATH_RESOLVING = BIT(1),
MESH_PATH_DSN_VALID = BIT(2),
MESH_PATH_FIXED = BIT(3),
MESH_PATH_RESOLVED = BIT(4),