If you wanted to quickly repatch an iSCSI connection from one switch to another - would iSCSI choke? Or would iSCSI simply back off and retransmit a few seconds later? I don't have a lab to replicate this. Thanks.
I would bring down the ISCSI connection and then switch over. This has to do with all of the associated network issues such as ARP or spanning tree. Even with portfast, I would not expect that you could swing the cable over fast enough so that TCP has enough opportunity to recover.