Now you know we prefer to be called Gurus than Geeks right? lol
1. No, switchmode was the only workaround to support disjoint layer 2 in previous versions. In 2.0 we have built in Disjoint Layer 2 support for EHM (End Host Mode). There is a LAN Uplink Manage wizard now where you can assign certain VLANs to certain uplinks. By default all systems operate in the usually way - all VLANs allowed on all uplinks unless explicitly configured otherwise. Each VLAN now has it's own Designated Receiver interface for incoming MCast & BCast traffic (previousl it was one DR for all).
2. Yes. Switch mode runs STP, so links will be blocked if you have multiple uplinks. In EHM there is no spanning tree as pinning is used to ensure host traffic never gets sourced out of more than one interface. Watch Brad's which explains switch vs. EHM. Keep in mind this is pre-2.0, but the conecepts other than Disjoint L2 support for EHM, all still apply.
3. Yes, switch mode is 100% supported by TAC. My preference is unless you have a dire need for Switch mode, stick with EHM. With Disjoint L2 support there should be few & far between reasons to use switch mode. ** Keep in mind switching between Switch mode & EHM is disruptive. Both switches reboot and you will have to apply the appropriate configuration. You will need a maintenance window to convert to/from.
4. Normally the decision to change between switch & EHM is during your intial deployment. But for customers wanting to change now with the Disjoint L2 support now, it will be a considerable task - not difficult, just needs to be properly planned. My team is going to run through some basic procedures & tests on changing over with a production system, and draft up a guide or video regarding it. I'll post it to CSC as soon as we're done. Brad Hedlund has a bunch of other great video's on UCS & networking operations. I'd suggest you have a watch through his series so you're 100% clear on the differences in functionality.
Introduction This article will help you understand the steps on how to
download the UCS licenses from the Cisco Systems website and then
installing it on the UCS. The redacted (blue lines) just covers up
certain numbers for privacy please do not take them...
Introduction This article will help you understand and educate the
customer on how to clear their "expired licenses"
(license-graceperiod-expired) from their UCS-M. If a customer just
purchased a license and needs a step by step guide on how to download
==================== VIC FNIC driver does not support Virtual Volumes (
second level LUN ID ) An enhancement request has been created to track
this feature - CSCux64473 UPDATE - 12-14-2016 We made some traction on
the enhancement request - The Fix is in t...