System Management
206
Basic System Configuration Guide
3HE 11010 AAAC TQZZA Edition: 01
6.2.1.1.2 Configuration Redundancy
Features configured on the active CSM are saved on the standby CSM as well.
When the active CSM fails, these features are brought up on the standby CSM that
takes over the mastership.
Even with modern modular and stable software, the failure of hardware or software
can cause the router to reboot or cause other service impacting events. In the best
circumstances, failure leads to the initialization of a redundant route processor, which
hosts the standby software configuration to become the active processor.
The 7705 SAR supports hot standby. With hot standby, the router image,
configuration, and network state are already loaded on the standby; it receives
continual updates from the active route processor and the swap over is immediate.
Newer-generation service routers like the 7705 SAR have extra processing built into
the system so that router performance is not affected by frequent synchronization,
which consumes system resources.
6.2.1.1.3 Component Redundancy
7705 SAR component redundancy is critical to reducing MTTR for the routing
system. Component redundancy consists of the following features:
• dual Control and Switching modules — for a highly available architecture,
redundant Control and Switching Modules (CSMs) are essential
• redundant power supply feed — a power feed can be removed without impact
on traffic
• redundant fan — if one fan fails, the others will continue to operate and provide
cooling to the system without impacting traffic
• hot swap — components in a live system can be replaced or become active
without taking the system down or affecting traffic flow to or from other modules
6.2.1.1.4 Accounting Configuration Redundancy
When there is a switchover and the standby CSM becomes active, the accounting
servers will be checked, and if they are administratively up and capable of coming
online (media present and so on), then the standby will be brought online and new
accounting files will be created at that point. Users must manually copy the
accounting records from the failed CSM.
To Next Page
Loading...
