CheckICMPHeader

CheckICMPHeader Element Documentation

NAME

CheckICMPHeader — Click element; checks ICMP header on ICMP packets

SYNOPSIS

CheckICMPHeader([KEYWORDS])

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

DESCRIPTION

Expects ICMP packets as input. Checks that the packet's length is sensible and that its checksum field is 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 IP 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 CheckICMPHeader will maintain detailed counts of how many packets were dropped for each possible reason, accessible through the drop_details handler. False by default.

ELEMENT HANDLERS

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

SEE ALSO

CheckIPHeader, CheckTCPHeader, CheckUDPHeader, MarkIPHeader

Generated by click-elem2man from ../elements/icmp/checkicmpheader.hh:7 on 2017/10/17.