hopfinder.sh - find good candidates for gateway monitoring (dpinger) in pfSense

hopfinder.sh

#!/bin/sh

# hopfinder for pfSense
# finds nearby upstream targets for gateway monitoring
# gist: e5df683d8b11dd68aef3255efc22e611

list_ifs() {
/usr/local/bin/php <<EOP
<?php
  require_once('interfaces.inc');
  \$a_gateways = return_gateways_array();
  foreach (\$a_gateways as \$idx => \$gw) {
    if ((\$gw['ipprotocol'] == 'inet') && (substr(\$gw['interface'],0,4) != "ovpn")) {
      printf("%s%s%s%s%s\n", \$gw['interface'], ' - ', \$gw['name'], ' - ', \$gw['gateway']);
    }
  }
?>
EOP
}

# requires interface as parameter
if [ -z "$1" ]; then
  echo "specify an interface:"
  list_ifs
  exit
fi

#clear the temp file that will store the trace results
o=/tmp/hops
:>$o

targets='
8.8.8.8
8.8.4.4
1.1.1.1
1.0.0.1
9.9.9.9
google.com
yahoo.com
cnn.com
github.com
nytimes.com
facebook.com
instagram.com
twitter.com
amazon.com
netflix.com
'

for t in $targets; do
  echo tracing $t
  #skip 1st hop (-M2) max 15 hops (-m15) use ICMP (-P icmp) 2 queries (-q2) 1s wait (-w1)
  #send stderr to bitbucket and filter out *s (no response)
  traceroute -i $1 -M2 -m15 -P icmp -q1 -n -w1 $t 2>/dev/null | awk '$2 != "*" { print $2 }' >>$o
done

#filter and reverse-sort results by frequency
sort $o | uniq -c | awk '$1 > 1 { print }' | sort -rn