5-3
Cisco ASR 1000 Series Aggregation Services Routers Software Configuration Guide
OL-16506-10
Chapter 5 High Availability Overview
Software Redundancy on the Cisco ASR 1000 Series Routers
Software Redundancy on the Cisco ASR 1000 Series Routers
This section covers the following topics:
•
Software Redundancy Overview, page 5-3
•
Second IOS Process on a Cisco ASR 1002 or 1004 Router, page 5-4
•
SSO-Aware Protocol and Applications, page 5-6
Software Redundancy Overview
On the Cisco ASR 1000 Series Routers, IOS runs as one of many processes within the operating system.
This is different than on traditional Cisco IOS, where all processes are run within Cisco IOS. See the
“IOS as a Process” section on page 1-7
for more information regarding IOS as a process on the Cisco
ASR 1000 Series Router.
This architecture allows for software redundancy opportunities that are not available on other platforms
that run Cisco IOS software. Specifically, a standby IOS process can be available on the same Route
Processor as the active IOS process. This standby IOS process can be switched to in the event of an IOS
failure, and can also be used to upgrade subpackage software in some scenarios as the standby IOS
process in an ISSU upgrade.
SPA
No
No
No
No
No standby configurations are
available for SPAs. If a SPA
fails, that particular SPA is
down and unable to forward
traffic.
In the event of a SPA shutdown,
all other SIPs and SPAs on the
router continue to be fully
operational.
SIP
No
No
No
No
No standby configurations are
available for SIPs. If a SIP fails,
all SPAs in that SIP are down
and unable to forward traffic.
In the event of a SIP shutdown,
all other SIPs and SPAs on the
router continue to be fully
operational.
Table 5-1
Hardware Redundancy Overview
Hardware
Support for Dual
Hardware
Configuration on
Cisco ASR 1001
Router
Support for Dual
Hardware
Configuration on
Cisco ASR 1002
Router
Support for
Dual Hardware
Configuration
on Cisco ASR
1004 Router
Support for
Dual Hardware
Configuration
on Cisco ASR
1006 Router
Failover Behavior