ssmping: 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 Debian possible default full paths are:

/usr/bin/ssmping - from package: ssmping

You may install the required package with command apt-get install {package}

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