geoiplookup6: 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/geoiplookup6 - from package: GeoIP

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

On Debian possible default full paths are:

/usr/bin/geoiplookup6 - from package: geoip-bin

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

Error in other languages:
geoiplookup6: bevel nie gevind nie
geoiplookup6: comandă negăsită
geoiplookup6: comando não encontrado
geoiplookup6: commande introuvable
geoiplookup6: command not found
geoiplookup6: käsku ei ole
geoiplookup6: không tìm thấy lệnh
geoiplookup6: komanda nerasta
geoiplookup6: Kommando nicht gefunden.
geoiplookup6: kommandot finns inte
geoiplookup6: komut yok
geoiplookup6: nie znaleziono polecenia
geoiplookup6: níor aimsíodh an t-ordú
geoiplookup6: no se encontró la orden
geoiplookup6: no s'ha trobat l'ordre
geoiplookup6: opdracht niet gevonden
geoiplookup6: parancs nem található
geoiplookup6: perintah tidak ditemukan
geoiplookup6: príkaz nenájdený
geoiplookup6: příkaz nenalezen
geoiplookup6: команда не найдена
geoiplookup6: командата не е открита
geoiplookup6: 命令找不到
geoiplookup6: コマンドが見つかりません