networking/devlink/devlink-trap.rst

20 packet with a TTL of 1. Upon routing the packet the device must send it to the
26 is called "packet trapping".
32 supported packet traps with ``devlink`` and report trapped packets to
36 bytes accounting and potentially report the packet to user space via a netlink
39 as it allows users to obtain further visibility into packet drops that would
44                                     Netlink event: Packet w/ metadata
76                                   | Trapped packet
89 The ``devlink-trap`` mechanism supports the following packet trap types:
112 The ``devlink-trap`` mechanism supports the following packet trap actions:
114   * ``trap``: The sole copy of the packet is sent to the CPU.
115   * ``drop``: The packet is dropped by the underlying device and a copy is not
117   * ``mirror``: The packet is forwarded by the underlying device and a copy is
120 Generic Packet Traps
123 Generic packet traps are used to describe traps that trap well-defined packets
128 .. list-table:: List of Generic Packet Traps
142        the packet is untagged or prio-tagged
243        failure during decapsulation (e.g., packet being too short, reserved
415        might be because of packet truncation or the I flag is not set.
422        include unexpected packet truncation.
439        This packet trap could include packets which do not pass an IP checksum
441        from packet truncation thus the total length field exceeds the received
442        packet length etc
454        This packet trap could include checksum errorrs, an improper UDP
499 Driver-specific Packet Traps
502 Device drivers can register driver-specific packet traps, but these must be
504 help debug packet drops caused by these exceptions. The following list includes
512 .. _Generic-Packet-Trap-Groups:
514 Generic Packet Trap Groups
517 Generic packet trap groups are used to aggregate logically related packet
523 .. list-table:: List of Generic Packet Trap Groups
529      - Contains packet traps for packets that were dropped by the device during
532      - Contains packet traps for packets that were dropped by the device during
535      - Contains packet traps for packets that hit an exception (e.g., TTL
538      - Contains packet traps for packets that were dropped by the device due to
541      - Contains packet traps for packets that were dropped by the device during
544      - Contains packet traps for packets that were dropped by the device during
547      - Contains packet traps for STP packets
549      - Contains packet traps for LACP packets
551      - Contains packet traps for LLDP packets
553      - Contains packet traps for IGMP and MLD packets required for multicast
556      - Contains packet traps for DHCP packets
558      - Contains packet traps for neighbour discovery packets (e.g., ARP, IPv6
561      - Contains packet traps for BFD packets
563      - Contains packet traps for OSPF packets
565      - Contains packet traps for BGP packets
567      - Contains packet traps for VRRP packets
569      - Contains packet traps for PIM packets
571      - Contains a packet trap for unicast loopback packets (i.e.,
574        the CPU usage, a packet trap policer with a low rate can be bound to the
577      - Contains packet traps for packets that should be locally delivered after
578        routing, but do not match more specific packet traps (e.g.,
581      - Contains packet traps for packets that should be routed through an
585      - Contains packet traps for various IPv6 control packets (e.g., Router
588      - Contains packet traps for PTP time-critical event messages (Sync,
591      - Contains packet traps for PTP general messages (Announce, Follow_Up,
594      - Contains packet traps for packets that were sampled by the device during
597      - Contains packet traps for packets that were trapped (logged) by the
600      - Contains packet traps for packets that were marked by the device during
603      - Contains packet traps for "Extensible Authentication Protocol over LAN"
606 Packet Trap Policers
611 packet rates that are several orders of magnitude higher compared to those that
615 devices usually include packet trap policers that are able to police the
619 supported packet trap policers with ``devlink``. The device driver can choose
620 to associate these policers with supported packet trap groups (see
621 :ref:`Generic-Packet-Trap-Groups`) during its initialization, thereby exposing
640 as the triggering of supported packet traps.