trafshow: 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 CentOS possible default full paths are:

/usr/bin/trafshow - from package: trafshow

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/trafshow - from package: netdiag

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

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