xorp_pimsm4: 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/lib/xorp/sbin/xorp_pimsm4 - from package: xorp

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

Error in other languages:
xorp_pimsm4: bevel nie gevind nie
xorp_pimsm4: comandă negăsită
xorp_pimsm4: comando não encontrado
xorp_pimsm4: commande introuvable
xorp_pimsm4: command not found
xorp_pimsm4: käsku ei ole
xorp_pimsm4: không tìm thấy lệnh
xorp_pimsm4: komanda nerasta
xorp_pimsm4: Kommando nicht gefunden.
xorp_pimsm4: kommandot finns inte
xorp_pimsm4: komut yok
xorp_pimsm4: nie znaleziono polecenia
xorp_pimsm4: níor aimsíodh an t-ordú
xorp_pimsm4: no se encontró la orden
xorp_pimsm4: no s'ha trobat l'ordre
xorp_pimsm4: opdracht niet gevonden
xorp_pimsm4: parancs nem található
xorp_pimsm4: perintah tidak ditemukan
xorp_pimsm4: príkaz nenájdený
xorp_pimsm4: příkaz nenalezen
xorp_pimsm4: команда не найдена
xorp_pimsm4: командата не е открита
xorp_pimsm4: 命令找不到
xorp_pimsm4: コマンドが見つかりません