Switch User Manual

• Use private VLANs to restrict traffic to pass only between data ports and the uplink
ports, thereby isolating adjacent ports within the same VLAN, and allowing you to
limit the total number of VLANs that need to be configured.
• Use protocol VLANs to restrict traffic to specified interfaces based on protocol type.
Traffic Prioritization – This switch prioritizes each packet based on the required
level of service, using eight priority queues with strict or Weighted Round Robin
Queuing. It uses IEEE 802.1p and 802.1Q tags to prioritize incoming traffic based on
input from the end-station application. These functions can be used to provide
independent priorities for delay-sensitive data and best-effort data.
This switch also supports several common methods of prioritizing layer 3/4 traffic to
meet application requirements. Traffic can be prioritized based on the priority bits in
the IP frame’s Type of Service (ToS) octet or the number of the TCP/UDP port.
When these services are enabled, the priorities are mapped to a Class of Service
value by the switch, and the traffic then sent to the corresponding output queue.
IP Routing – The switch provides Layer 3 IP routing. To maintain a high rate of
throughput, the switch forwards all traffic passing within the same segment, and
routes only traffic that passes between different subnetworks. The wire-speed
routing provided by this switch lets you easily link network segments or VLANs
together without having to deal with the bottlenecks or configuration hassles
normally associated with conventional routers.
Routing for unicast traffic is supported with the Routing Information Protocol (RIP)
and the Open Shortest Path First (OSPF) protocol.
RIP – This protocol uses a distance-vector approach to routing. Routes are
determined on the basis of minimizing the distance vector, or hop count, which
serves as a rough estimate of transmission cost.
OSPF – This approach uses a link state routing protocol to generate a shortest-path
tree, then builds up its routing table based on this tree. OSPF produces a more
stable network because the participating routers act on network changes predictably
and simultaneously, converging on the best route more quickly than RIP.
Router Redundancy – The Virtual Router Redundancy Protocol (VRRP) uses a
virtual IP address to support a primary router and multiple backup routers. The
backups can be configured to take over the workload if the master fails or to load
share the traffic. The primary goal of this protocol is to allow a host device which has
been configured with a fixed gateway to maintain network connectivity in case the
primary gateway goes down.
Address Resolution Protocol – The switch uses ARP and Proxy ARP to convert
between IP addresses and MAC (i.e., hardware) addresses. This switch supports
conventional ARP, which locates the MAC address corresponding to a given IP
address. This allows the switch to use IP addresses for routing decisions and the
corresponding MAC addresses to forward packets from one hop to the next. You can
configure either static or dynamic entries in the ARP cache.
Proxy ARP allows hosts that do not support routing to determine the MAC address
of a device on another network or subnet. When a host sends an ARP request for a
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Description of Software Features
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