SG300 DHCP IP Address Conflict

[daniel.hindenlang]

Hi Community,

we've Set up several SG300 in our Network. Every SG300 is connected to the Master Switch. Each SG300 operates in a own VLAN and running a DHCP Server for his VLAN. Every DHCP Server is running with a other IP Range.

Sometimes a new Client connects to a Switch, the Client gets a IP Address Conflict.

I've tested some scenarios. My test brought the following results:

• the DHCP Server (running on the SG300) serves a already allocated IP to the new Client, but only when the client is requesting a IP via Option 50.
• the DHCP Server doesen't offers expired IP to a new Client.
• When a new Client connects to the network and requests a already allocated IP, the DHCP Server sends a NAK to the Client which uses the requested IP and than offers the IP to the new Client

I have no idea why this happen. Is there a problem with the DHCP Service on the SG300? Did I miss something to configure?

This is a realy strange behavior, maybe somebody can explain?

I've attached my Test report and the Switch configuration with wich I've tested.

Thanks in advance

Regards

Daniel

[Mark Malone]

If you look through the forum here you will see numerous issues of these sg300s and dhcp acting strangely, if your not on the latest firmware you could upgrade the switch to try and fix it

[daniel.hindenlang]

Hi Mark,

thanks for the fast reply.

SG300 running Firmware 1.4.3 which is the latest firmware.

Regards

Daniel

[Mark Malone]

If its a bug you could log it with the small business support they may be able to recommend when a newer release is coming out or they may have a workaround

you could temporarily roll back as well see if that fixes it for you

http://www.cisco.com/cisco/web/solutions/small_business/small_business_support_and_resources.html

[daniel.hindenlang]

Just opened a Case. Thanks for your assistance.

I will report the result here