Higher Education

Hi,

I can see too many BAD-ADDRESS entry in DHCP leased address on wireless clients, what could be the reason, how can I restrict this, any advise please ?

Thank you.

Microsoft DHCP will mark any lease or reservation as BAD_ADDRESS if it detects an IP conflict on the network.  I guess the first thing I would ask is if you can give us a little information about what your environment looks like.

noticed wifi user connection issue, checked dhcp and two scopes out of 17 for that ssid shows full, lease details shows too many BAD-ADDRESS, lease time is 15 mins, even then those bad address lease time doesnt match with this setting.

Am I right in assuming this is DHCP on a Microsoft server, rather than something different?

If so, can you please post a screenshot of the entries you're seeing?

There can be a number of reasons why this might occur. The following is an example.

http://social.technet.microsoft.com/Forums/windowsserver/en-US/0ef9b4b1-f14d-4e55-8760-150ddd22420b/dhcp-server-bad-address-issue?forum=winserverNIS

Can you also confirm if there is a DHCP relay/helper in the client VLANs? I would imagine there is? What is it? I've seen some IP routing devices corrupt DHCP relayed messages before.

Depending on what the above reveals, the next best step might be to run a sniffer on the server to watch the DHCP requests coming in and replies out. That will almost certainly identify root cause.