Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 366)

336 Multi-Service IronWare Switching Configuration Guide
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SuperSpan™
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SuperSpan™
SuperSpan is a Brocade STP enhancement that allows Service Providers (SPs) to use STP in both
SP networks and customer networks. The SP devices are Brocade devices and are configured to
tunnel each customer’s STP BPDUs through the SP. From the customer's perspective, the SP
network is a loop-free non-blocking device or network. The SP network behaves like a hub in the
sense that the necessary blocking occurs in the customer network, not in the SP.
The interfaces that connect the SP to a customer's network are configured as SuperSpan boundary
interfaces. Each SuperSpan boundary interface is configured with a customer ID, to uniquely
identify the customer's network within SuperSpan.
Figure 57 shows an example SuperSpan implementation. In this example, an SP's network is
connected to multiple customers. Each customer network is running its own instance of standard
STP. The Brocade devices in the SP are running SuperSpan.
FIGURE 57 SuperSpan example
In this example, the SP network contains two devices that are running SuperSpan. The SP is
connected to two customer networks. Each customer network is running its own instance of STP.
SuperSpan prevents Layer 2 loops in the traffic flow with each customer while at the same time
isolating each customer’s traffic and spanning tree from the traffic and spanning trees of other
customers. For example, the SP devices provide loop prevention for Customer 1 while ensuring that
Customer 1’s traffic is never forwarded to Customer 2. In this example, customer 1 has two
interfaces to the SP network, ports 1/1 and 1/2 connected to SP 1. The SP network behaves like a
non-blocking hub. BPDUs are tunneled through the network. To prevent a Layer 2 loop, customer
1’s port 1/2 enters the blocking state.
Customer ID
SuperSpan uses a SuperSpan customer ID to uniquely identify and forward traffic for each
customer. You assign the customer ID as part of the SuperSpan configuration of the Brocade
devices in the SP. In
Figure 57 , the spanning trees of customer 1 and customer 2 do not interfere
with one another because the SP network isolates each customer’s spanning tree based on the
SuperSpan customer IDs in the traffic.