2 NICS and a switch port

[cto_securelogic]

When traffic is being balanced between two server NICs to a switch (2950) port, do the two different MAC addresses between the NICs cause STP changes or mac address table churn at the switch?

Thanks

[Georg Pauwen]

Hello,

Spanning Tree would only be affected if your server NICs are capable of sending BPDUs, which they are not likely to. The switch just sees one MAC address coming from each port and does not do anything with it, other than the load balancing.

As a side note, it is advisable to configure the portfast and bpduguard features on the port where the server NICs are connected to (with the ´spanning-tree portfast´ and ´spanning-tree bpduguard enable´ commands). The first one allows the port to skip the normal listening and learning phases of STP, the second one shits down the port in case a BPDU capable device is mistakenly attached to the port.

Regards,

GP

[cto_securelogic]

Thanks for your reply...to delve a little deeper - will the mac address table in the switch contain two mac addresses associated with the port?

Thanks

[Georg Pauwen]

Hello,

the switch will indeed see both MAC addresses.

Regards,

GP