What is a requirement for performing Cisco IOS ISSU on the Cisco IOS XE-based ASR 1006 and
ASR 1013 routers?
A.
must use consolidated package mode
B.
must use subpackage mode
C.
must have redundant RPs
D.
must have owner and nonowner SDRs
Explanation:
Software Upgrade with Dual IOS Processes on a Single RP Overview
To complete a software upgrade of an individual subpackage using dual IOS processes on a single RP, SSO must first be enabled.
Software upgrade with dual IOS processes is useful for upgrading the individual RP subpackages that can be upgraded without a router reload. Importantly, note that most subpackage upgrades in a single RP configuration require a hardware reload to complete (whether an RP reload for an RP subpackage, an ESP reload for the ESPBase subpackage, a SIP reload for a SIPBase subpackage, or a SPA reload for the SIPSPA subpackage), so limited interruption upgrades for single RP configurations are not available in most upgrade scenarios.
Cisco IOS XE Software Package Compatibility for ISSU
Cisco IOS XE release compatibility using the ISSU process utilizes the SSO functionality to preserve state while software versions on the router differ, as during an upgrade. Most SSO-capable features in each Cisco IOS XE release are ISSU capable. ISSU is only supported if SSO is enabled in the configuration and the system is in a steady state (SSO ready state has been achieved). ISSU compatibility depends on the set of specific feature clients that are in use and whether they support ISSU. All ISSU upgrades include at least one IOS switchover operation. It is important to understand which features are in use and whether these features are ISSU compatible.
Cisco ASR1006 or ASR 1013 series routers are hardware-redundant chassis. The hardware-redundant chassis has two ESP linecards and two RPs which exchange state using hardware links. The Cisco ASR1002 and ASR1004 Series Routers are not hardware redundant, but are software-redundancy capable. The nonredundant chassis has a single RP and a single ESP, but allows the operation of up to two IOS processes on the single RP to exchange states locally.
http://www.cisco.com/c/en/us/td/docs/routers/asr1000/configuration/guide/chassis/asrswcfg/issu.html#pgfId-1152341
C.
must have redundant RPs