xfhdlcst: 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/xfhdlcst - from package: ax25-xtools

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

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