Operation Over A Common Ipv4 Network - Cisco ASR 5000 series Product Overview

▀ Features and Functionality - Licensed Enhanced Feature Support
Figure 124. Loopback Interface Configuration
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Operation Over a Common IPv4 Network

The PDIF supports L2 switching to enable carriers not using dynamic routing between the core nodes to perform an
online upgrade.
In the example below, the SRP virtual MAC address is configured for the SRP-activated loopback address for the
subnet. This allows the standby chassis to seamlessly assume the active role in the network after a switchover. Attached
devices continue to send to the same SRP virtual MAC address and the currently active chassis responds to ARP
requests for the shared loopback IP address. This scheme allows fast standby-to-active transitions, since the SRP virtual
MAC address does not change during the switchover.
▄ Cisco ASR 5000 Series Product Overview
Primary PDIF Chassis
Ingress
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Ingress
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Backup PDIF Chassis
Active SRP – Activated loopback interface
Standby SRP – Activated loopback interface
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Context C
Egress
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SRP
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SRP
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Egress
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Context C
Packet Data Interworking Function Overview
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