FIP Snooping in a Switch StackFIP snooping supports switch stacking as follows:• A switch stack configuration is synchronized with the standby stack unit.• Dynamic population of the FCoE database (ENode, Session, and FCF tables) is synchronized with the standby stack unit. The FCoEdatabase is maintained by snooping FIP keep-alive messages.• In case of a failover, the new master switch starts the required timers for the FCoE database tables. Timers run only on the masterstack unit.Using FIP SnoopingThere are four steps to configure FCoE transit.1 Enable the FCoE transit feature on a switch.2 Enable FIP snooping globally on all Virtual Local Area Networks (VLANs) or individual VLANs on a FIP snooping bridge.3 Configure the FC-Map value applied globally by the switch on all VLANs or an individual VLAN.4 Configure FCF mode for a FIP snooping bridge-to-FCF link.For a sample FIP snooping configuration, refer to FIP Snooping Configuration Example.Statistical information is available for FIP Snooping-related information. For available commands, refer to the FCoE Transit chapter in theDell Networking OS Command Line Reference Guide.FIP Snooping PrerequisitesBefore 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 theswitch for lossless Ethernet connections (refer to the Data Center Bridging (DCB) chapter). Dell Networking recommends also enablingenhanced 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 PFCparameters in a DCBx exchange with a peer are not synchronized, FIP and FCoE frames are dropped on the port after you enable the FIPsnooping 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 theportmode hybrid command).• configure tagged VLAN membership on each FIP snooping port that sends and receives FCoE traffic and has links with an FCF, ENodeserver, 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 isconfigured for non-default 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.326 FIP Snooping
