Cisco SRW2008P User Guide - Page 51

Chapter 5 Advanced Configuration •• Root Provides the lowest cost path to forward packets to root device. •• Designated Indicates the port or LAG via which the designated device is attached to the LAN. •• Alternate Provides an alternate path to the root device from the root interface. •• Backup Provides a backup path to the designated port path toward the Spanning Tree leaves. Backup ports occur only when two ports are connected in a loop by a point-to-point link. Backup ports also occur when a LAN has two or more connections connected to a shared segment. •• Disabled Indicates the port is not participating in the Spanning Tree. Mode Indicates the current Spanning Tree mode. The Spanning Tree mode is selected in the Global STP screen. The possible field values are: •• Classic STP Indicates that Classic STP is enabled on the device. •• Rapid STP Indicates that Rapid STP is enabled on the device. •• Multiple STP Indicates that Multiple STP is enabled on the device. Interface Priority Defines the interface priority for specified instance. The default value is 128. Path Cost Indicates the port contribution to the Spanning Tree instance. The range should always be 1-200,000,000. Designated Bridge ID Indicates that the bridge ID number that connects the link or shared LAN to the root. Designated Port ID Indicates that the Port ID number on the designated bridge that connects the link or the shared LAN to the root. Designated Cost Indicates that the default path cost is assigned according to the method selected on the Spanning Tree Global Settings screen. Forward Transitions Indicates the number of times the port has changed from Forwarding state to Blocking state. Remaining Hops Indicates the hops remaining to the next destination. Multicast > IGMP Snooping Multicast > IGMP Snooping When IGMP Snooping is enabled globally, all IGMP packets are forwarded to the CPU. The CPU analyzes the incoming packets and determines: •• Which ports want to join which Multicast groups? •• Which ports have Multicast routers generating IGMP queries? •• Which routing protocols are forwarding packets and Multicast traffic? Ports requesting to join a specific Multicast group issue an IGMP report, specifying that Multicast group is accepting members. This results in the creation of the Multicast filtering database. Enable IGMP Snooping Indicates if IGMP Snooping is enabled on the device. IGMP Snooping can be enabled only if Bridge Multicast Filtering is enabled. VLAN ID Specifies the VLAN ID. IGMP Status Indicates if IGMP snooping is enabled on the VLAN. Auto Learn Indicates if Auto Learn is enabled on the device. If Auto Learn is enabled, the device automatically learns where other Multicast groups are located. Enables or disables Auto Learn on the Ethernet device. Host Timeout Indicates the amount of time host waits to receive a message before timing out. The default time is 260 seconds. MRouter Timeout Indicates the amount of the time the Multicast router waits to receive a message before it times out. The default value is 300 seconds. 8-Port 10/100/1000 Gigabit Switch with Webview 45