socket2socket: 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/socket2socket - from package: desproxy

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

Error in other languages:
socket2socket: bevel nie gevind nie
socket2socket: comandă negăsită
socket2socket: comando não encontrado
socket2socket: commande introuvable
socket2socket: command not found
socket2socket: käsku ei ole
socket2socket: không tìm thấy lệnh
socket2socket: komanda nerasta
socket2socket: Kommando nicht gefunden.
socket2socket: kommandot finns inte
socket2socket: komut yok
socket2socket: nie znaleziono polecenia
socket2socket: níor aimsíodh an t-ordú
socket2socket: no se encontró la orden
socket2socket: no s'ha trobat l'ordre
socket2socket: opdracht niet gevonden
socket2socket: parancs nem található
socket2socket: perintah tidak ditemukan
socket2socket: príkaz nenájdený
socket2socket: příkaz nenalezen
socket2socket: команда не найдена
socket2socket: командата не е открита
socket2socket: 命令找不到
socket2socket: コマンドが見つかりません