Hi all,

I've had a look around here, and online but to no avail. I wondered if anybody had come across this issue before.

I've got a 2860ac which is setup with two SSIDs, one 5G and one 2.4Ghz. This also provides internet access for Sky Broadband. It's at the front of the house, which means we don't get internet access at the back. These work perfectly.

Some time ago, I set up two wireless routers, which are wired to the 2860ac. Let's call these A and B. Each have a different SSID to all others. Each has been given a static IP and specified in the Bind IP to Mac section of the 2860n router config, with same IP being set on the router itself (both A and B). DHCP is only enabled on the 2860ac. I've preassigned a static range on the 2860ac, I think DHCP starts at 192.168.1.50, with IP's lower than reserved for static IPs.

Just to clarify, all devices are on the 192.168.1.0/24 range

I've got a few other devices set on the Bind IP to Mac config, i.e. cameras etc. These are generally connecting via A or B successfully. Some other devices in the house, also connect to A or B quickly and easily.

The problem seems to occur when I connect my macbook pro to A or B via WiFi. DHCP doesn't assign, and I end up 'unconnected'. Running wireshark, i just get a bunch of DHCP discover packets and that's it. No assigment and ACK. If I do the same experiment on one of the SSIDs which is hosted by the 2860ac, DHCP works perfectly - DHCP packets are quickly followed by allocation and ACK.

*Its as if DHCP discovery packets are not reaching the DHCP server, or replies are not reaching the wireless client on the access points A & B*

As I've said though there are some devices in the house which connect almost immediately to these access points (A or B). I've not been unable to understand wny.

Anybody have any ideas? Could it be to do with DHCP lease times? The Macbook Pro?

Any help appreciated!
Doug

my 2860 had a bug a couple of firmware versions ago (don't if it still exists in current versions, haven't bothered to check) where it showed the exact same behaviour IF the UDP flood protection was on (confirmed via Wireshark)

What's the make of "A" and "B"?

I vaguely recall a problem with binding IP to MAC and wireless. If you've set A and B with static addresses you don't need to bind them as well.

If you're using routers just as Access Points I presume you are using "LAN" ports to connect them, not the "WAN" port. The WAN port will almost certainly block DHCP.

A few years ago I used to use a 2600 as router along with a BT Homehub providing WiFi. The Homehub was assigned a static IP and as far as possible had its ADSL modem turned off, and DHCP disabled. It couldn't get its own LAN-side IP address via DHCP, that had to be static.

Make sure you haven't tick this under firewall/defense setup
Block IP packet from LAN with inconsistent source IP addresses.