Users Guide

When you enable FCoE transit, the switch snoops FIP packets on VLANs enabled for FIP snooping and allows
legitimate sessions. FCoE and FIP packets are dropped on VLANs disabled for FIP snooping. When you disable
FCoE transit, the S5000 operates as a pure Layer 2 switch that switches FCoE and FIP packets.
As soon as you enable the FCoE transit feature on a switch-bridge, existing VLAN-specific and FIP snooping
configurations are applied. The FCoE database is populated when the switch connects to a converged
network adapter (CNA) or FCF port and compatible DCB configurations are synchronized. By default, all FCoE
and FIP frames are dropped unless specifically permitted by existing FIP snooping-generated ACLs. You can
reconfigure any of the FIP snooping settings.
If you disable FCoE transit, FIP and FCoE traffic are handled as normal Ethernet frames and no FIP snooping
ACLs are generated. The VLAN-specific and FIP snooping configuration is disabled and stored until you re-
enable FCoE transit and the configurations are re-applied.
NOTE: When you configure the S5000 switch as an NPIV proxy gateway and enable Fibre Channel
capability (the feature fc command), FIP snooping is automatically enabled on all VLANs on the switch
using the default FIP snooping settings.
FIP Snooping Prerequisites
Before you enable FCoE transit and configure FIP snooping on a switch, ensure that certain conditions are
met.
A FIP snooping bridge requires data center bridging exchange protocol (DCBx) and priority-based flow
control (PFC) to be enabled on the switch for lossless Ethernet connections (refer to the
Data Center Bridging (DCB)chapter). Dell Networking recommends also enabling enhanced transmission
selection (ETS); however, ETS is recommended but not required.
If you enable DCBx and PFC mode is on (PFC is operationally up) in a port configuration, FIP snooping is
operational on the port. If the PFC parameters in a DCBx exchange with a peer are not synchronized, FIP and
FCoE frames are dropped on the port after you enable the FIP snooping feature.
For VLAN membership, you must:
• create the VLANs on the switch which handles FCoE traffic (use the interface vlan command).
• configure each FIP snooping port to operate in Hybrid mode so that it accepts both tagged and
untagged VLAN frames (use the portmode hybrid command).
• configure tagged VLAN membership on each FIP snooping port that sends and receives FCoE traffic and
has links with an FCF, ENode server, or another FIP snooping bridge (use the tagged port-type
slot/port
command).
The default VLAN membership of the port must continue to operate with untagged frames. FIP snooping is
not supported on a port that is configured for nondefault untagged VLAN membership.
Important Points to Remember
• Enable DCBx on the switch before enabling the FIP Snooping feature.
• To enable the feature on the switch, configure FIP Snooping.
• To allow FIP frames to pass through the switch on all VLANs, enable FIP snooping globally on a switch.
• A switch can support a maximum eight VLANs. Configure at least one FCF/bridge-to-bridge port mode
interface for any FIP snooping-enabled VLAN.
FCoE Transit 395