icmpinfo: 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

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/sbin/icmpinfo - from package: icmpinfo

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