Dell MX9116n EMC SmartFabric OS10 User Guide Release 10.5.1 - Page 349

compute the shortest path to reach a switch in the fabric. The name server service uses these routes to synchronize the name server database across the fabric. Hence, FSPF helps in building the fabric connectivity. Configure the same hold-time value on all the switches to ensure a consistent route convergence, and to avoid intermittent forwarding loop. When you configure a shorter hold-time, the route update is faster. FSPF detects the link failures in the fabric and recomputes the next available shortest path to reach the destination domain. FSPF also updates the change in route such as addition of new link or removal of existing link and when the link goes up or down. Distributed domain name server (DNS) DNS is responsible for name server registration and management of Nx_Ports that are attached to the switch. The registered name entries are stored in the local database. Each switch exchanges its name server information with other switches in the fabric to maintain a synchronized and distributed name service. Each switch in the fabric must distribute switch registered state change notification (SW_RSCNs) throughout the fabric whenever there is a change in its local database. Topology changes trigger SW_RSCN, and NS queries. Each switch forwards the SW_RSCN packets on the FSPF computed path towards the other switches in the fabric. System logs The system log file contains the system logs for the following events: ● FC port operationally up ● Principal switch selection ● Domain ID assignment ● Port isolation ● Fabric or nondisruptive reconfiguration data ● Disruptive fabric reconstruction ● Error conditions when ELP or EFP exchange fails, and when the port goes into isolated state Restrictions and limitations This section lists the restrictions, and limitations of the multiswitch fabric feature. ● The multiswitch feature does not support Virtual E-ports (VE), BB_credit configuration, autoport mode, static FC route, zone merging, ESC exchange between switches, and switch port initialization. ● Only one vfabric is supported per switch in the multiswitch mode. ● Interoperability with other vendors, such as non-OS10 switches are not supported. ● Due to hardware limitations, multiswitch fabric feature does not support ECMP at the NPU level. ● Incremental update for shortest path route computation is not supported. The shortest path computation always runs for the entire fabric. ● ACL entries that are installed for control and data traffic use statically reserved CAM entries. Dynamic ACL space allocation is not supported. ● The switch supports zoning configurations like the F port mode. Configure the same zoning configurations on all switches in the fabric to avoid the Logical Unit Numbers (LUNs) being lost, during topology changes. NOTE: When you enable the multiswitch feature, the N port mode is disabled. The default port mode is the F port. During the multiswitch fabric configuration, if you delete the E Port mode, the port mode resets to the default, F port mode. Multiswitch Fabric (E Port) Limitations The following limitations are applicable in 10.5.1: ● The multiswitch feature does not support Virtual E ports (VE), BB_credit configuration, autoport mode, static FC route, zone merging, ESC exchange between switches, and switch port initialization. ● Only one vfabric is supported per switch in multiswitch mode. ● Interoperability with other vendors, such as non-OS10 switches are not supported. ● Due to hardware limitations, the multiswitch fabric feature does not support ECMP at the NPU level. ● Incremental update for shortest path route computation is not supported. The shortest path computation always runs for the entire fabric. Fibre Channel 349