udpong: command not found

Have You tried accessing the binary with the full path?

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/udpong - from package: librdmacm-utils

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

On Debian possible default full paths are:

/usr/bin/udpong - from package: rdmacm-utils

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