Please add a local DNS server, like dnsmasq, to the ER605. It's a bug for a business router that's running DHCP to not be able to resolve local host names.

@MarcoE I just bought my ER605 yesterday and I'm running into this problem now. This is the 2nd dealbreaker I've found. The other is being able to configure only one NO-IP DDNS hostname. I should...

@phongtom I'm having the same problem. ER605 and several NO-IP hostnames.