iksperf: 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/iksperf - from package: iksemel-utils

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

On Debian possible default full paths are:

/usr/bin/iksperf - from package: libiksemel-utils

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

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