ipa-client-install: 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/sbin/ipa-client-install - from package: ipa-client

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

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