desproxy-dns: 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/desproxy-dns - from package: desproxy

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