Extreme

Extreme Networks Technical Brief

SummitStack Stacking Technology
Introduction
Extreme Networks® SummitStack™ stacking technology enables the physical connection of up to eight individual Summit® switches together as a single logical unit. This logical unit reduces the management overhead of fixed configuration switches by behaving as a single switch with a single IP address and a singlepoint of authentication. In ExtremeXOS®, Extreme Networks edge-to-core modular operating system, a stack is controlled by a master switch, called the master. The master switch runs the full-featured version of ExtremeXOS and is responsible for maintaining all of the software tables for all the switches in the stack. There can only be one master switch in a stack of switches. All switches in the stack,including the master switch, are called nodes. A stack of Summit switches can be thought of as a Virtual Chassis™. Each node acts as if it was occupying a slot in a chassis and is controlled by the master. The high-speed stacking links function like the backplane links of a chassis. Stacking offers customers a flexible way to increase switch density and capacity, provides port configurationchoices, and controls upfront capital requirements. SummitStack permits mixing and matching Summit switches in a multi-platform stack to provide the port configuration you need, from Ethernet, Fast Ethernet, Gigabit Ethernet to 10 Gigabit Ethernet, in copper, Power over Ethernet (PoE), Power over Ethernet Plus (PoE-plus) and fiber optic interfaces. The master switch stores any configuration informationfor the stack in its primary and secondary flash memory. Since the master switch has the knowledge of the state and the configuration of all the other switches in the stack, it can respond to all external requests for those switches. For example, the master switch can respond to a request for SNMP information from all ports within the stack. SummitStack is supported through dedicated stackingport functionality with specific stack cables or through the use of existing 10 Gigabit Ethernet ports to stack the switches together. The latter option allows for physical flexibility when stacking needs to be carried over longer distances than is supported in the dedicated stacking cables. SummitStack is an Extreme Networks solution for fixed configuration switches to provide simplified yet agileoperations for scalable converged networks. The mechanism supports many network topology designs and is Ethernet based requiring no new hardware or interfaces. This technology brief introduces different varieties of stacking and can help clarify areas of potential confusion. Topics covered include: different topologies possible with stacking, aspects of configuring and managing a stack, whathappens during stack topology changes, and how to configure a stack for the first time.

SummitStack Varieties
The following table shows the different stacking options available on Extreme Networks stacking products.

Table 1
Stacking Options SummitStack Speed per Link (HDX) 10 Gbps Cable Type & Lengths 0.5m, 1.5m, 3.0m 20G Stacking Cable Summit Switch Series Summit X250 Summit X450a Summit X450eSummit X460 Summit X480 Summit X650 Summit X450a Summit X450e Summit X460 Summit X480 Summit X650 Summit X460 Summit X480 with conversion cable to SummitStack256 Summit X650 Summit X650

SummitStack-V

10 Gbps

0.5m – 100m SFP+, XFP, XENPAK, 10GBaseT

SummitStack-V80 20 Gbps SummitStack128 SummitStack256 SummitStack512 32 Gbps 64 Gbps 128 Gbps

0.5m – 100m QSFP+ only 0.5m, 1.0m, 3.0m0.5m, 1.0m, 3.0m 0.5m, 1.0m, 3.0m

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SummitStack Stacking Technology—Page 1

Extreme Networks Technical Brief

SummitStack Topologies
Figure 1 presents a graphical representation of a stack and some of the terms that describe stack conditions. A stack is the collection of all nodes that are cabled together in a stack. A stack topology is...