nrattach: 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/sbin/nrattach - from package: ax25-tools

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

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