5-4
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
On the Cisco ASR 1006 Router, the second IOS process can run only on the standby Route Processor.
Two IOS processes on the same Router Processor are not possible for any Cisco ASR 1000 Series Router
that supports dual RP hardware redundancy configurations since the second Route Processor can support
a standby IOS process. An overview of software redundancy is shown in
Table 5-2
.
Second IOS Process on a Cisco ASR 1002 or 1004 Router
For Cisco ASR 1002 and 1004 routers, Route Processor Redundancy and Stateful Switchover can be
used to switch between IOS processes. RPR and SSO need to be configured by the user, however,
because a second IOS process is not available by default on Cisco ASR 1002 and 1004 routers.
Table 5-2
summarizes the software redundancy opportunities available with the second IOS process for
the Cisco ASR 1002 and 1004 routers.
ISSU cannot be used to upgrade consolidated packages on Cisco ASR 1002 or 1004 Routers, and only
a few subpackages can be upgraded individually using ISSU through the use of dual IOS processes on
the same Route Processor. See the
“Route Processor Redundancy” section on page 5-5
for more
information on which subpackages can be upgraded using ISSU in a dual RP setup.
Table 5-2
Software Redundancy Overview
Router
Support for Two IOS
Processes on Same
Route Processor
Support for a
Second IOS
Process on Standby
Route Processor
Explanation
Cisco ASR 1001
Router
1
1.
If a critical process, such as the ESP or the SIP fails on the Cisco ASR 1001 Router, then the entire chassis reloads.
Yes
N/A
The Cisco ASR 1001 Router only
supports one RP, so dual IOS processes
run on the lone RP.
Cisco ASR 1002
Router
Yes
N/A
The Cisco ASR 1002 Router only
supports one RP, so dual IOS processes
run on the lone RP.
Cisco ASR 1004
Router
Yes
N/A
The Cisco ASR 1004 Router only
supports one RP, so dual IOS processes
run on the lone RP.
Cisco ASR 1006
Router
No
Yes
The Cisco ASR 1006 Router supports a
second Route Processor, so the second
IOS process can only run on the
standby Route Processor.
Table 5-3
Software Redundancy Options for Cisco ASR 1002 and 1004 Routers
Router
Default HA
Setting
Options with 2 GB or
DRAM
Options with 4 GB or
DRAM
Cisco ASR 1002 Router
None
None
None, RPR, SSO
Cisco ASR 1004 Router
None
None
None, RPR, SSO
