User guide

Software Overview
ExtremeWare 7.2e Installation and User Guide 29
For more information on VLANs, see Chapter 5.
Spanning Tree Protocol
The switch supports the IEEE 802.1D Spanning Tree Protocol (STP), which is a bridge-based mechanism
for providing fault tolerance on networks. STP enables you to implement parallel paths for network
traffic, and ensure that:
• Redundant paths are disabled when the main paths are operational.
• Redundant paths are enabled if the main traffic paths fail.
A single spanning tree can span multiple VLANs.
For more information on STP, see Chapter 11.
Quality of Service
ExtremeWare has Policy-Based Quality of Service (QoS) features that enable you to specify service levels
for different traffic groups. By default, all traffic is assigned the normal QoS policy profile. If needed,
you can create other QoS policies and apply them to different traffic types so that they have different
guaranteed minimum bandwidth, maximum bandwidth, and priority. For more information on Quality
of Service, see Chapter 7.
Unicast Routing
The switch can route IP traffic between the VLANs that are configured as virtual router interfaces. Both
dynamic and static IP routes are maintained in the routing table. The following routing protocols are
supported:
• RIP version 1
• RIP version 2
• OSPF version 2
For more information on IP unicast routing, see Chapter 12.
IP Multicast Routing
The switch can use IP multicasting to allow a single IP host to transmit a packet to a group of IP hosts.
ExtremeWare supports multicast routes that are learned by way of the Protocol Independent Multicast
(sparse mode). For more information on IP multicast routing, see Chapter 14.
Load Sharing
Load sharing allows you to increase bandwidth and resiliency by using a group of ports to carry traffic
in parallel between systems. The load sharing algorithm allows the switch to use multiple ports as a
single logical port. For example, VLANs see the load-sharing group as a single virtual port. The
algorithm also guarantees packet sequencing between clients. For more information on load sharing, see
Chapter 4.