> Does this include firewall routers or guest lan (or another internal > vswitch) between these servers ? Is there any information about this I > can > read about this, is this something a LAN administrator would know ?
This is typically called a "router on a stick" or "lollipop" configuration in the network world. Your network engineering people should recognize that immediately. At least part of what they're worrying about is the possibility for the guest or the OSA to somehow be configured as a layer 2 bridge, and somehow get elected as the root bridge of the configuration, which would set up a possible source of major disruption if the guest dies and you have to hold a root bridge election in a complex network in the middle of the production day -- which can take several minutes (in a really large network, it can approach an hour or more) and EVERYTHING will come to a halt. Packet forwarding must be completely suspended while the election is underway, so you can immediately see why this is a Bad Thing. The defaults in 802.1q (especially if you are taking an out-of-the-book literal implementation of 802.1q like the VSWITCH) are OK for simple networks, but since the VSWITCH doesn't yet have any ability to adjust the bridge priority or convergence settings and doesn't yet do VTP, you can cause yourself some serious pain if your network engineers just relied on Cisco or Nortel to set the defaults such that the bigger switches win. This problem is trivially avoidable if your core switches are correctly configured to always win elections, but there are an awful lot of people who drop layer 2 devices directly into a network without considering this little detail. (*grumble* Would have been nice to just have the OSA run IOS, so this could be done just like any other network device and you could trivially limit the scope of convergence problems so that they only mung the guests inside the box ....*sigh* Another case of being too far ahead of the pack...*grumble*)
