Now it is time to upgrade D-Link router 850L to new version, 1.12WW.
Here is official download link
Look at the release notes:
Firmware: FW1.12.B05(Release)Hardware: A1Date:2014/10/06Note:1. Update CN channel table2. Support No-IP DDNS serverProblems Resolved:1. Fix gmx mail server issue.2. Fix WAN/LAN IP conflict issue.3. Fix HW NAT throughput issue
It is only for Hardware version A1.