NAME

Monitoring::Sneck::Checks::neighbors - checks how full the ARP and NDP neighbor tables are

VERSION

Version 0.0.1

SYNOPSIS

neighbors|perl:neighbors
neighbors_big_l2|perl:neighbors -w 60 -c 80

DESCRIPTION

Checks the ARP table, for IPv4, and the NDP one, for IPv6, against gc_thresh3, past which the kernel will not add entries, so traffic to new neighbors is dropped with only a kernel log line saying so. This bites on big layer 2 networks.

The kernel also counts each time a table was full. That count is kept in a state file, see "read_state" in Monitoring::Sneck::Checks::base, and any rise since the last run is CRITICAL, as packets were dropped.

The sizes come from /proc/net/stat. Only Linux has this, others are UNKNOWN.

OPTIONS

- -w, --warning :: Range of percent of gc_thresh3 used. Default :: 80

- -c, --critical :: Range of percent of gc_thresh3 used. Default :: 90

METHODS

check

Does the check.