3Com 3CRDSF9PWR-US User Guide - Page 231

Switch Features 231 Table 13 Features of the OfficeConnect Managed Fast Ethernet PoE Switch (continued) Feature Configuration File Management DHCP Clients Domain Name System Edge Port Full 802.1Q VLAN Tagging Compliance IGMP Snooping LACP Link Aggregated Groups Description The device configuration is stored in a configuration file. The Configuration file includes both system wide and port specific device configuration settings. The system can display configuration files in the form of a collection of CLI commands, which are stored and manipulated as text files. Dynamic Host Client Protocol. DHCP enables additional setup parameters to be received from a network server upon system startup. DHCP service is an on-going process. Domain Name System (DNS) converts user-defined domain names into IP addresses. Each time a domain name is assigned, the DNS service translates the name into a numeric IP address. For example, www.ipexample.com is translated to 192.87.56.2. DNS servers maintain domain name databases and their corresponding IP addresses. STP can take up to 30-60 seconds to converge. During this time, STP detects possible loops, allowing time for status changes to propagate and for relevant devices to respond. 30-60 seconds is considered too long of a response time for many applications. The Edge Port option bypasses this delay, and can be used in network topologies where forwarding loops do not occur. IEEE 802.1Q defines an architecture for virtual bridged LANs, the services provided in VLANs, and the protocols and algorithms involved in the provision of these services. An important requirement included in this standard is the ability to mark frames with a desired Class of Service (CoS) tag value. IGMP Snooping examines IGMP frame contents, when they are forwarded by the device from work stations to an upstream Multicast router. From the frame, the device identifies work stations configured for Multicast sessions, and which Multicast routers are sending Multicast frames. LACP uses peer exchanges across links to determine, on an ongoing basis, the aggregation capability of various links, and continuously provides the maximum level of aggregation capability achievable between a given pair of systems. LACP automatically determines, configures, binds and monitors the port binding within the system. The system provides up to four Link Aggregated Groups (LAGs). Aggregated Links may be defined, each with up to eight member ports, to form a single LAG. LAGs provide: ■ Fault tolerance protection from physical link disruption ■ Higher bandwidth connections ■ Improved bandwidth granularity ■ High bandwidth server connectivity ■ LAG is composed of ports with the same speed, set to full-duplex operation.