netkit-rcp: 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 Debian possible default full paths are:

/usr/bin/netkit-rcp - from package: rsh-client

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