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Cisco CRS-1 Carrier Routing System Multishelf System Upgrade and Conversion Guide
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Chapter2 Converting to an Integrated Switch System
Benefits of the CiscoCRS-1 Multishelf Integrated Switch Solution

Cisco CRS-1 Multishelf Integrated Switch Solution

When the CiscoCatalyst 65xx switches are phased out of the multishelf network, the new 22-port SCGE
cards, which are installed in the Cisco CRS-1 Multishelf FCCs, are connected directly to the
Cisco CRS-1 Multishelf LCC RPs. The Cisco CRS-1 RP is a system controller that performs route
processing and distributes forwarding tables to the line cards. A lthough each routing system contains
two RPs, only one RP is active at a time. The other RP operates in standby mode if the active RP fails.
To perform the conversion, you need to know how to view and use the STP on the Cisco Catalyst 65xx
switch through the console port.
Note The Cisco Catalyst 65xx switches are typically configured so that one is the root of the spanning tree,
and the other one is the backup root. All the ports in the root switch are in the forwarding state.
Before the conversion to the 22-port SCGE, if you have two ports from the RP connected to a
Cisco Catalyst 65xx switch, you should see one RP port in forwarding state, and the other RP port in
blocked state.
RSTP is used to break the interchassis loops in the Layer 2 control network.
Note Loops can happen only when a port is transitioning from a down state to an up state.
Benefits of the Cisco CRS-1 Multishelf Integrated Switch Solution
The following benefits are described for migrating from a Cisco Catalyst 65xx switch-based control
network for the multishelf system to a bundled 22-port SCGE integrated switch solution:
•The Cisco Catalyst switches are configured with Cisco IOS software through a separate
command-line interface (CLI). But the integrated 22-port SCGE sw itches are configured from the
Cisco CRS-1 router console by using the Cisco IOS XR so ftware, which is the same operating
system used by the Cisco CRS-1 router. The control network is easie r to connect and manage.
•There is no longer any need for two dedicated Catalyst switches per multichassis system.
Naming Conventions
The following naming conventions are used in this document:
•The fabric chassis upper cage shelf controller card and its slot are both referre d to as SC0.
•The lower cage shelf controller card and slot are referred to as the SC1.
•There are two SC cards in every FCC for the purpose of redundancy.
•The active Cat6K remains active in the CiscoCRS-1 Multishelf control network.