This chapter describes configuring virtual loopback and null interfaces to improve routing reliability and manage network traffic effectively.
Prerequisites for configuring virtual interfaces
This topic describes the prerequisites that you must meet before you configure virtual loopback, null, and virtual IPv4 interfaces on the Cisco 8000 Series Router.
Virtual loopback interface
This topic describes the virtual loopback interface, its always-up single-endpoint behavior, and its typical uses as a routing-protocol session endpoint and a target for ping verification on the Cisco 8000 Series Router.
Null interface
This topic describes the null interface, which is always up, and provides an alternative to access lists for filtering unwanted traffic on the Cisco 8000 Series Router.
Virtual management interface
This topic describes the virtual management interface that enables management access to the Cisco 8000 Series Router from a single address.
Active and standby RPs and virtual interface configuration
This topic describes how virtual interfaces persist across active and standby route processor (RP) failover on the Cisco 8000 Series Router, and how to ensure that protocols such as TACACS+, SNMP, NTP, and syslog use the virtual IPv4 address as their source address.
Configure virtual loopback interfaces
This topic describes how to configure a basic virtual loopback interface on the Cisco 8000 Series Router.
Configure null interfaces
This topic describes how to configure a basic null interface on the Cisco 8000 Series Router by entering global configuration mode, entering the Null 0 interface configuration mode, saving the configuration, and verifying the interface.
Configure virtual IPv4 interfaces
This topic describes how to configure an IPv4 virtual address for the management Ethernet interface on the Cisco 8000 Series Router so that you can access the router from a single virtual address that persists across route processor (RP) failover.