AIX

Hmm,
My perception was different, I was taking into account the actual failover of network from one VIOS to other VIOS.

Since you have only one VIO server, the dual redundancy of HEA is termed as SEA. Like when you allow the ethernet bridging, it is considering and naming it as SEA (as it is sharing the ports). unless you don't do SEA, you cannot share the network adapter with clients, so in simple language, we are creating SEA to share the network with client (allowing them to connect to outer world).

But, make sure before you do allow ethernet bridging, you do etherchanneling on the HEA.

I recommend you look at Nigel's movies: AIX Movies
He has a section on IVM - much better that anything I made - way back when.