I am trying to understand LACP in the context of STP.
Case 1. There is a server connecting to 2 different switches for redundancy purpose and a bond interface created with 2 slaves physically connecting to each switches with a bonding mode 802.3ad. Is it correct? As per IEEE, 802.3ad is active-active but STP blocks one of the server uplinks. What am I missing here.
Case 2: There is a server connecting to 2 different switches in mlag through bond interface with 2 slaves in 802.3ad mode. Now what is the mac address used for communication in a normal case. It cannot use both the physical mac's otherwise it will confuse the switch. Which mac will be taken? Is it bond primary configuration?
Best Answer
The proper way is to use active-passive (failover) bonding. LACP to multiple switches can only be achieved when using two (or more) stacked switches. By stacking switches they will act as one virtual switch. STP should be used as a safety mechanism only.
If I am right the mac of the first interface in the bond will be used and copied to all interfaces in the bond (and the bond itself)