If I am not wrong, it is ok to use same ip with Hp Ilo4 and proxmox. But I am having some "connection refused" issues for ilo and can not access its gui. Is it possible proxmox is having some issue with iptables and ilo ?
Not really... Each IP should be unique as otherwise computers in the network are not sure where they should send the traffic to. I assume the iLO is having its own network interface?