I also am having big issues with the DHCP server on the DIR-880. I sent the email below to DLink support on Sept 5th (one week ago) and have received no response at all. This is unlike them since tech support for my old DIR-655 support has been great, even years after I bought it. Maybe they simply have no answers yet?
Here is a copy of what I sent to support. I've edited the message below for clarity since I sent it to them. Is anyone else seeing the same things?
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It seems impossible to reserve specific IP addresses for specific devices in the DHCP server in the DIR-880L, Rev: 1.01.
I have about 50 devices on my LAN. Some (like IP cameras, printers, servers, access points, main router) are static. My PC's and wireless devices are dynamic. My DHCP server range is limited from 192.168.xx.60 through .xx.160 I have a number of port forwarding rules that reference devices that are assigned dynamic IP addresses, but they obviously have to receive the same IP address each time they are connected. So having DHCP reservations are essential to me. My old DIR-655 did this, no problem.
The new method of trying to reserve DHCP addresses is truly awful and doesn't work.
Here are some issues I have noticed so far:
1) The "connected clients" list also shows devices outside of the DHCP range that are assigned static IP addresses. They look exactly the same as the dynamically assigned IP nodes. They should be flagged as static IP, don't you think?
2) The clients almost all show up as "Unknown" with "Unknown Vendor". The MAC address is not shown. How can one possibly determine which device is which? At least you should show the MAC address!
NOTE: When I run FING on my LAN, it can determine the vendor of almost all my devices. If this free LAN discovery tool can display MAC addresses & vendors, shouldn't the DIR-880L be able to do so as well?
3) Some of the devices don't show up. eg: on my LAN, 192.168.xx.146 has never appeared on the client list. This IP address is within the DHCP range. The node is alive and I can ping it and communicate with it. It can send emails out through the WAN. But it isn't on the DIR-880L client list. So I have no hope of assigning a static IP to it.
4) I can't change an existing dynamically assigned IP address to reserve a different one. If I type in my desired IP address, it is overridden with the existing IP. I can only reserve the IP that happens to be assigned to the device right now?
5) No KICK (Revoke) function to force a device to get a new IP address.
6) No indication whether a reservation attempt was successful. Is an IP address on the client list actually reserved? or static? or subject to change at any time? There is no way to tell. There is no DHCP reservation table that I can view.
7) Your support videos and FAQs for DIR series routers describe how to reserve DHCP addresses on all your previous routers. But you have nothing for the DIR-880L. (Maybe because this function simply doesn't work anymore?)
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The "Connected Client" screen rewrites itself every few seconds, which is expected. I currently have 35 devices active on my LAN. The nodes are solid and my network is stable. However the client list varies each cycle, sometimes displaying as few as 7 clients, sometimes 26. And all number of nodes in between. (But the router never actually manages to display all of my nodes!) So the node you were about to try to edit may disappear or move somewhere else in the client list. There is no discernable order to the list.
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Please generate a F/W revision ASAP that restores the old DHCP reservation functionality. I had actually been hoping for a larger DHCP table in this new router. It appears that I now have no useable reservation table at all.
OTHER ISSUES:
1) Accessing the GUI on this router does not always reset the "log off" timer. Even when I am actively entering data into the router, it will log off periodically, wiping out any changes made on the current page.
2) Why are there only 15 Port Forwarding and 15 Virtual Server rules on the DIR-880L ?? Even my old DIR-655 had 24 of each. I don't happen to need all of them, but other users might. Why cripple the new router, particularly since it (should) have so much more hardware resources available?
I really feel like boxing this thing up and returning it, but I'm willing to wait if it looks like DLink is actually making an effort to fix this.