IBM server connected to 4948 - gives error

[bsn1980in]

Hi

Products

IBM Server with Ethernet Server Connectivity Module, 6 GB Ethernet ports - Qty 1

Cisco 6509 - Oty 02

Cisco 4948 - Qty 02

Earlier setup:  IBM server was connected to 6509-1 and 6509-2 and both switches were connected over a trunk link.  Everything worked fine without any error.

New setup: 4948-1 connected to both 6509 and 4948-2 is also connected to 6509-2.  This gives an error

%C4K_EBM-4-HOSTFLAPPING: Host 00:21:5E:30:0B:0A in vlan 112 is flapping between port Te1/49 and port Gi1/44

                                   

In old setup, server MAC is only learned through 6509-1 port.  No spanning-tree blocked ports were on either of switch.

However in new setup, ports from both 4948 towards 6509-2 are in blocked state.

It is clearly a layer 2 loop.  How can I avoid it? And why it is not occuring when directly conneting server to both 6509 switches.

rgds/bsn

[chinkevi_2]

can i ask what is the vendor of the switch module in the bladeserver?  If it is an old Dlink i remember it tends to misbehave.

Please also check the spanning tree on the switch module.

if we still don't see the issue, i think we need to dwell into how the bladeserver is configured for internal mngt and external connection.