pingAll: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/pingAll - from package: cjdns-tools

You may install the required package with command yum install {package}

Error in other languages:
pingAll: bevel nie gevind nie
pingAll: comandă negăsită
pingAll: comando não encontrado
pingAll: commande introuvable
pingAll: command not found
pingAll: käsku ei ole
pingAll: không tìm thấy lệnh
pingAll: komanda nerasta
pingAll: Kommando nicht gefunden.
pingAll: kommandot finns inte
pingAll: komut yok
pingAll: nie znaleziono polecenia
pingAll: níor aimsíodh an t-ordú
pingAll: no se encontró la orden
pingAll: no s'ha trobat l'ordre
pingAll: opdracht niet gevonden
pingAll: parancs nem található
pingAll: perintah tidak ditemukan
pingAll: príkaz nenájdený
pingAll: příkaz nenalezen
pingAll: команда не найдена
pingAll: командата не е открита
pingAll: 命令找不到
pingAll: コマンドが見つかりません