Se você tem um servidor que bloqueia pacotes ICMP pelo firewall, como saber se ele está online utilizando o comando ping ?

Resposta: Utilizando o tcpping, um script feito por Richard van den Berg que trago aqui para o VivaoLinux.

Requisitos:
-bash
-tcptraceroute

Como usar:
tcpping www.servidorcomfirewall.com.br

Abraços!

• Download tcpping
• Enviar nova versão

Esconder código-fonte

#!/bin/sh
#
# tcpping: test response times using TCP SYN packets
#          URL: http://www.vdberg.org/~richard/tcpping.html
#
# uses tcptraceroute from http://michael.toren.net/code/tcptraceroute/
#
# (c) 2002-2005 Richard van den Berg <richard@vdberg.org> under the GPL
#               http://www.gnu.org/copyleft/gpl.html
#
# 2002/12/20 v1.0 initial version
# 2003/01/25 v1.1 added -c and -r options
#                 now accepting all other tcptraceroute options
# 2003/01/30 v1.2 removed double quotes around backquotes
# 2003/03/25 v1.3 added -x option, courtesy of Alvin Austin <alvin@crlogic.com>
# 2005/03/31 v1.4 added -C option, courtesy of Norman Rasmussen <norman@rasmussen.org>

ver="v1.4"
format="%Y%m%d%H%M%S"
d="no"
c="no"
C="no"
ttl=255
seq=0
q=1
r=1
w=3
topts=""

usage () {
   name=`basename $0`
   echo "tcpping $ver Richard van den Berg <richard@vdberg.org>"
   echo
   echo "Usage: $name [-d] [-c] [-C] [-w sec] [-q num] [-x count] ipaddress [port]"
   echo
   echo "        -d   print timestamp before every result"
   echo "        -c   print a columned result line"
   echo "        -C   print in the same format as fping's -C option"
   echo "        -w   wait time in seconds (defaults to 3)"
   echo "        -r   repeat every n seconds (defaults to 1)"
   echo "        -x   repeat n times (defaults to unlimited)"
   echo
   echo "See also: man tcptraceroute"
   echo
}

_testsite() {
   myseq="${1}"
   shift
   [ "${c}" = "yes" ] && nows=`date +${format}`
   [ "${d}" = "yes" ] && nowd=`date`
   ttr=`tcptraceroute -f ${ttl} -m ${ttl} -q ${q} -w ${w} $* 2>/dev/null`
   host=`echo "${ttr}" | awk '{print $2 " " $3}'`
   if echo "${ttr}" | egrep "\[(open|closed)\]" >/dev/null 2>&1; then
      rtt=`echo "${ttr}" | awk '{print $5}'`
   else
      rtt=`echo "${ttr}" | awk '{print $4}'`
   fi
   not=`echo "${rtt}" | tr -d ".0123456789"`
   [ "${d}" = "yes" ] && echo "$nowd"
   if [ "${c}" = "yes" ]; then
      if [ "x${rtt}" != "x" -a "x${not}" = "x" ]; then
         echo "$myseq $nows $rtt $host"
      else
         echo "$myseq $nows $max $host"
      fi
   elif [ "${C}" = "yes" ]; then
      if [ "$myseq" = "0" ]; then
         echo -n "$1 :"
      fi
      if [ "x${rtt}" != "x" -a "x${not}" = "x" ]; then
         echo -n " $rtt"
      else
         echo -n " -"
      fi
      if [ "$x" = "1" ]; then
         echo
      fi
   else
      echo "${ttr}" | sed -e "s/^.*\*.*$/seq $myseq: no response (timeout)/" -e "s/^$ttl /seq $myseq: tcp response from/"
   fi
#       echo "${ttr}"
}

while getopts dhq:w:cr:nNFSAEi:f:l:m:p:s:x:C opt ; do
   case "$opt" in
      d|c|C) eval $opt="yes" ;;
      q|w|r|x) eval $opt="$OPTARG" ;;
      n|N|F|S|A|E) topt="$topt -$opt" ;;
      i|l|p|s) topt="$topt -$opt $OPTARG" ;;
      f|m) ttl="$OPTARG" ;;
      ?) usage; exit ;;
   esac
done

shift `expr $OPTIND - 1`

if [ "x$1" = "x" ]; then
   usage
   exit
fi

max=`echo "${w} * 1000" | bc`

if [ `date +%s` != "%s" ]; then
   format="%s"
fi

if [ "$x" = "" ]; then
   while [ 1 ] ; do
      _testsite ${seq} ${topt} $* &
      pid=$!
      if [ "${C}" = "yes" ]; then
         wait $pid
      fi
      seq=`expr $seq + 1`
      sleep ${r}
   done
else
   while [ "$x" -gt 0 ] ; do
      _testsite ${seq} ${topt} $* &
      pid=$!
      if [ "${C}" = "yes" ]; then
         wait $pid
      fi
      seq=`expr $seq + 1`
      x=`expr $x - 1`
      if [ "$x" -gt 0 ]; then
         sleep ${r}
      fi
   done
fi

exit

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