of_inet_addr_exn ip is the Ipaddr.t equivalent of the
Unix.inet_addrip IPv4 address. Raises Ipaddr.Parse_error if
ip is not a valid representation of an IPv4 address.
of_inet_addr_exn ip is the Ipaddr.t equivalent of the
Unix.inet_addrip IPv6 address. Raises Ipaddr.Parse_error if
ip is not a valid representation of an IPv6 address.