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Elements / UDP

CheckUDPHeader

checks UDP header on UDP/IP packets

SYNOPSIS§

CheckUDPHeader([KEYWORDS])

Batching: Batching natively supported
Ports: 1 input, 1-2 outputs
Processing: agnostic, but output 1 is push

DESCRIPTION§

Expects UDP/IP packets as input. Checks that the UDP header length and checksum fields are valid. Pushes invalid packets out on output 1, unless output 1 was unused; if so, drops invalid packets.

Prints a message to the console the first time it encounters an incorrect packet (but see VERBOSE below).

Keyword arguments are:

  • VERBOSE — Boolean. If it is true, then a message will be printed for every erroneous packet, rather than just the first. False by default.
  • DETAILS — Boolean. If it is true, then CheckUDPHeader will maintain detailed counts of how many packets were dropped for each possible reason, accessible through the drop_details handler. False by default.
  • CHECKSUM — Boolean. If it is true, the UDP checksum is validated. True by default.

ELEMENT HANDLERS§

  • count (read-only) — Returns the number of correct packets CheckUDPHeader has seen.
  • drops (read-only) — Returns the number of incorrect packets CheckUDPHeader has seen.
  • drop_details (read-only) — Returns a text file showing how many erroneous packets CheckUDPHeader has seen, subdivided by error. Only available if the DETAILS keyword argument was true.

SEE ALSO§

CheckIPHeader, CheckTCPHeader, CheckICMPHeader, MarkIPHeader

Generated by click-elem2man from ../elements/tcpudp/checkudpheader.hh:7 on 2026/11/02.