FIXED IP FIXED MAC WIRELESS_IP WIRELESS_MAC
192.168.20.19 F8:B4:6A:E5:0C:90 192.168.20.229 DC:FB:48:AA:B5:09
192.168.20.29 F8:B4:6A:EC:1C:5D 192.168.20.230 DC:FB:48:AA:B5:E0

I had the above config in my Strict bind table. The 2nd row was a new Dell Elitebook. 1st row an existing laptop - same part number.
1st row worked fine for years.

Then I added the 2nd device. Wireless worked fine on the new device.

Both devices configured for DHCP. Obviously Router dealing out IP config.

However, no matter what I did, the Router ALWAYS dished out an IP address from the pool that did not match the pre-assigned address for the fixed MAC (192.168.20.29 ). Hence no internet access was allowed.

Even changing the laptop IP config to static ( with 192.168.20.29) and removing the strict bind entry had a very strange effect : the laptop could not PING the router - even though the MAC address of the router was found in the laptop arp cache. If the strict bind entry was kept in the router, it "looked" like the router had the laptop MAC in its cache. The moment it was removed, it disappeared.

Also, changing laptop back to DHCP & removing the strict bind entry resulted in router giving out a pool IP address - but that address never appeared in the router ARP cache. Which I find a little bizarre.

Now for the Fix !

Removing the 1st strict bind entry ( 192.168.20.19 - the old laptop ) and retaining the entry, everything works fine.


I have added many devices over the years, and I have never ever seen anything like this before

( Caveat : quite old firmware - not too keen to upgrade before Christmas !!! )

I've seen similar behaviour with IP's that are set by binding the IP(strict not configured) where the router will use the IP/MAC configured in IP-bind in the ARP table regardless of the device having a different IP. The only fix was to remove if from the binding list.
The effect this had was that trying to ping or connect to the device failed.

Note in the configuration: If Strict Bind is enabled, unspecified LAN clients in the selected subnets cannot access the Internet.

The behaviour change with having the strict option de-selected should be that the IP/MAC should always appear in the ARP table.

By any chance do you have the Dell Optimiser running? Try uninstalling that as it may be affecting the network (switching between LAN/WLAN).

Of course the advice is also to update to the latest firmware and retest. As the 2860 is now effectively end of support (the last release 3.92 was a important security fix !) the firmware is probably as stable as it's ever going to get.