findnodes: 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/findnodes - from package: cjdns-python

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

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