netdump-server: 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 CentOS possible default full paths are:

/usr/sbin/netdump-server - from package: netdump-server

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