Dell S5000 Deployment/Configuration Manual page 60

Dell Networking S5000: Deployment of a Converged Infrastructure with FCoE
Figure 67: Dell S5000 acting as a NPIV Proxy Gateway and Dell MXL as FSB
One thing to note in Figure 67 above is that a separate link is needed for FCoE from the MXL to the
S5000; the reason for this is because FCoE is not supported over VLT. In this topology, if running
Rapid Spanning Tree Protocol (RSTP) as recommended when VLT is employed on the upstream
switches, it is important that the FCoE links are removed from the RSTP topology as we have
multiple links going from the MXL to the S5000. Additionally, we can have a different topology such
as that shown below in Figure 68 where a single link/port-channel takes converged traffic up to the
S5000 from each MXL switch. We are now separating LAN and SAN traffic at the S5000 rather than the
MXL. The advantage of this topology is that we don't need a separate link for FCoE; additionally, since
the blade server still has one server CNA port connecting to each MXL, we still have LAN and SAN
redundancy.
This topology can be used both with the Dell MXL and Dell PowerEdge M I/O Aggregator (IOA) blade
switch. With IOA, the 40 GbE connection would be used in 4 x 10GbE mode as that is the only mode
supported; a single 40GbE fiber/copper DAC cable can still be used in connecting the 40GbE ports but
the switch will treat the 40GbE link as 4 x 10GbE links. This topology would be the only deployment
model for Dell IOA because all uplink ports on the IOA are automatically part of one LAG, so there
would be no option to use VLT on the S5000 down to the IOA for LAN and have a separate uplink
from the IOA up to the S5000 for FCoE.
60 Deployment of a Converged Infrastructure with FCoE
Deployment/Configuration Guide