In our case we have an open Wi-Fi SSD for guest internet access. Sometimes the Peplink Balance its DHCP server assigns IPv4 addresses to DHCP client request. However the client doesn’t seem to be receiving the corresponding UDP answer packet for their request, at least the IP is not assigned. I have the idea that this happens as soon as clients enter the edge of the Wi-Fi radio reach, where signal is low, usable bandwidth is low, and a lot of packet loss occurs.
A possible solution (I haven’t checked for technical sensibility) to retry sending server to client packet(s) for DHCP assignment requests, until the IP address does respond to a ping request (and before the client sents out a new DHCP assignment request because a time-out timer is expiring).
Or way more detailed debug possibilities that give insight in what happens in the “DORA process”.
An example Wi-Fi client device with failure to acquire an IPv4 address and Peplink Balance logs the “DHCP Server: 192.168.x.x assigned 192.168.x.x to eX:fX:eX:7X:5X:7X, lease time 2678400” message:
Channel: 124 (11na)
Signal: 7.4% (-87 dBm)
TX Rate: 13 Mbps
RX Rate: 13.5 Mbps
Though there are also Wi-Fi client devices for which the Peplink Balance DHCP server doesn’t log an assignment message:
Channel: 11 (11ng)
Signal: 32% (-77 dBm)
TX Rate: 0 bps
RX Rate: 0 bps
Channel: 11 (11ng)
Signal: 7.4% (-87 dBm)
TX Rate: 0 bps
RX Rate: 1 Mbps
Channel: 6 (11ng)
Signal: 15% (-84 dBm)
TX Rate: 0 bps
RX Rate: 1 Mbps