Microsoft ES4612 Switch User Manual


 
Description of Software Features
1-5
1
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 – Hot Standby Router Protocol (HSRP) and Virtual Router
Redundancy Protocol (VRRP) both use 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 these
protocols 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
remote network, the switch checks to see if it has the best route. If it does, it sends
its own MAC address to the host. The host then sends traffic for the remote
destination via the switch, which uses its own routing table to reach the destination
on the other network.
Multicast Filtering – Specific multicast traffic can be assigned to its own VLAN to
ensure that it does not interfere with normal network traffic and to guarantee
real-time delivery by setting the required priority level for the designated VLAN. The
switch uses IGMP Snooping and Query at Layer 2 and IGMP at Layer 3 to manage
multicast group registration.