D-Link DES 6000 Product Manual - Page 48

Modular Ethernet Switch User's Guide ♦ State Enables or disables the port. This amounts to turning the port on or off. ♦ Speed/Duplex Selects the desired Speed and Duplex settings for the port. Possibilities include: Auto, 100M/Full, 100M/Half, 10M/Full, or 10M/Half. Choosing Auto enables NWay auto-configuration on the port. If the port is a Gigabit Ethernet port, 1000M/Full will be displayed in this field. Gigabit ports also support auto-negotiation. ♦ Flow Ctrl Toggles flow control On or Off. Flow control is useful during periods of heavy network activity when the Switch's buffers can receive too much traffic and fill up faster than the Switch can forward the information. In such cases, the Switch will intervene and tell the transmitting device to pause to allow the information in the port buffer to be sent. ♦ Priority Selects Normal, High or Low. The Switch has two packet queues where incoming packets wait to be processed for forwarding; a high priority and low priority queue. The high priority queue should only be used for data in which latency can have adverse affects on the function of an application, such as video or audio data, where latency can produce distorted sounds and images. Packets in the low priority queue will not be processed unless the High priority queue is empty. Setting the port priority to High will deliver all packets arriving at the port to the high priority queue, a Low setting will send them all to the low priority queue. The Normal setting causes the port to examine the packet for an IEEE 802.1p/Q priority tag. If no tag exists, the packet will be sent to the low priority queue. If the priority tag field in the packet header contains a value of 0-3, the packet will be placed in the low priority queue; a value of 4-7 causes the packet to be placed in the high priority queue. ♦ Port Lock When Enabled, automatic learning for all stations connected to this port will stop and entries in the Forwarding Table for all devices residing on this port will age out. The only traffic this port will allow is traffic from machines whose MAC address is manually entered in the Static Forwarding Table. ♦ Broadcast Storm Rising Action This setting will be activated when a Broadcast Storm Rising Threshold is met. When triggered, the port can be configured to Do Nothing, Blocking or Block & Trap. The Do Nothing setting causes the switch to operate normally, in other words, ignore the broadcast storm condition. The Blocking setting causes the port to drop all broadcast frames, thus isolating the broadcast storm. Block & Trap performs the same action as Blocking, except it also sends a trap to the designated Trap Recipient informing them of the situation. For more information on broadcast storms, please refer to the previous chapter. ♦ Broadcast Storm Rising Threshold This setting defines a ceiling for the number of broadcast packets per second on this port. Once met, the Broadcast Storm Rising Action (above) will be triggered. The assigned number should be high enough to allow normal broadcast packets (which comprise significant traffic) to be let through, while being low enough so that broadcast storms can be detected early. ♦ Broadcast Storm Falling Action This setting will be activated when the Broadcast Storm Rising Threshold and then the Broadcast Storm Falling Threshold are each met. This setting can be configured to Do Nothing, Forwarding or Forward & Trap. The Do Nothing setting causes the switch to operate normally, that is, to ignore the situation. If the port had met the Broadcast Storm Rising Action criteria and started Blocking broadcast packets, it will continue doing so. The Forwarding setting causes the port to begin forwarding broadcast frames, thus removing the Blocking state imposed by the Broadcast Storm Rising Action. Forward & Trap performs the same action as Forwarding, except it also sends a trap to the designated Trap Recipient informing them of the situation. ♦ Broadcast Storm Falling Threshold This setting defines the number of broadcast packets per second on this port which will trigger the Broadcast Storm Falling Action (above). This threshold will only trigger an action if the Broadcast Storm Rising Threshold has first been reached. The assigned number should be high enough to allow normal broadcast packets (which comprise significant traffic) to be let through as early as possible, while being low enough so that broadcast storms are completely eliminated. Using the Console Interface 43