Too often, I encounter network administrators mistakenly disconnecting clients with a 0.0.0.0 IP address. This usually happens after noticing the IPv4 address of a client under a specific access point (AP) go to 0.0.0.0. However, in 99% of these cases, the client is functioning perfectly fine the gateway can still ping the client. Despite this, administrators disconnect the client, assuming there’s an issue, until I explain that it’s unnecessary.
Note: In this example, it’s not 0.0.0.0, but you get the idea.
I believe the mechanism in cnMaestro could be improved. While it’s debatable whether this behavior warrants a change, I’m sharing what I frequently observe in indoor enterprise environments.
This issue typically occurs with roaming clients during a re-association request. It seems that the client IP field under the AP is updated only based on the DHCP offer or probe. My question is: can we enhance this by using the last known IP address from the re-association frame to update the client table more quickly?
In most cases where I observe the 0.0.0.0, the client has been connected for less than 5 minutes. Often, if the client is re-associating with the same AP or network (and the DHCP lease is still valid), it will reuse its existing IP address without sending a new DHCP request.
During a typical re-association request:
A client may request a new DHCP lease, but this depends on whether the client believes it needs a new IP address or if the network forces it to obtain one. In most networks I’ve seen, clients don’t actively perform actions that lead to the 0.0.0.0 IP address showing up under the AP’s client tab.
Suggested improvements
- Use the last known IP address from the re-association frame to update the client table immediately.
- Speed up the process of displaying the correct IP address, especially during the critical moments after re-association.
This would reduce confusion and prevent unnecessary manual disconnections by administrators.
Let’s discuss if this approach is feasible or if further refinements can be made to cnMaestro to address this issue effectively.
Thank you!