can't ping access network after plug in pc to an other switch of the network stack of HP 5120

[Infomax74]

Hi, we have a stack of HP Procurve 5120 in a server room , and in an other network room we have a stack or HP Procurve 5120 connected to the 5120 of the server room.

When we plug in a pc on the 5120 switch and then we plug in in the 5120 in the netwok room, the pc get an ip from the dhcp, but he can't access the network, or ping the network.

 if we wait 24h, the network on this PC work.

what can we check ?

[Vince-Whirlwind]

I'm not sure I understand.

Are you saying you are physically moving your laptop from one switch stack to the other?

Is it the same VLAN/subnet at both locations?

Where is the router for that subnet?

can the laptop ping its default GW?

Does the laptop's local switch show the laptop's MAC address against the correct port?

[Infomax74]

Hi, yes we physically moved the desktop PC from a stack of HP 5120 to an other stak of HP 5120.

first stack : 2 HP 5120 in the server room

other stack of 4 HP 5120 in the other network room.

The port on the switch is hybrid with vlan 1 for data and vlan 204 for voice vlan .

There were already a PC on the other switch which i disconnected to connect this new pc.

Thos se two stack of HP 5120 are conencted with an HP 3800 . 2 pair from the first HP 5120 to the HP 3800.

And 4 pair from the other stack of HP 5120 .

the router is the HP 3800 .

When we move the PC he get an ip from the DHCP but he can't ping the router. 

We did'nt test if he can ping other PC from the same stack or switch (we will test that) .

no the switch dont show the correct  mac address on the port, The mac address is on the port from the original switch.

Thanks

[Vince-Whirlwind]

I'm confused by your last paragraph but I think you need to look into clearing MAC ON TH 5120s or clear ARP on the 3800s

[Infomax74]

we alerady cleared mac adress and it did'nt resolve the problem.

The problem is so strange !

we think it's an ARP problem, but dont know what to do !

thanks