4510 switch issue

[brotherad]

We use a 4510 for user access in our facility.  One of the users has a unmanaged netgear switch plugged into it.  Whenever he plugs a laptop into his netgear switch, then gives the device back to the user and he plugs it back into his port (also on the 4510).  It does not get an ip address.  After further investigation is appears the mac address table always has the mac address of the port where the netgear is plugged in.  The only way I can get it to work is to unplug the netgear swtich or clear the mac address table.  Does anyone know why this is happening or what can be done to update the table or get the 4510 to recognize that the device has been unpluged from the netgear.  We did not have this issue in the past, it appears to have just started within the last few weeks.

[Richard Primm]

What is the code version on the 4k? Which sup are you using?

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[paul driver]

Hello

do you have any port security set?
is the netgear attaching.to.an.access.port which is allocated to a dhcp vlan

res
paul


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[brotherad]

The version of code is 15.0(1r)SG5 and its on Sup 7-E

Yes there is port security and yes its attaching to a port that is allocated to a DHCP vlan. 

Thanks,

Anthony