High Availability - Draytek Vigor2960 Series User Manual

The UPnP function dynamically adds port mappings on behalf of some UPnP-aware
applications. When the applications terminate abnormally, these mappings may not be
removed.
4 4 . . 8 8 . . 5 5 H H i i g g h h A A v v a a i i l l a a b b
The High Availability (HA) feature refers to the awareness of component failure and the
availability of backup resources. The complexity of HA is determined by the availability
needs and the tolerance of system interruptions. Systems, provides nearly full-time
availability, typically have redundant hardware and software that make the system available
despite failures.
The high availability of the Vigor2960 Series is designed to avoid single points-of-failure.
When failures occur, the failover process moves processing performed by the failed
component (the "Master") to the backup component (the "Slave"). This process remains
system-wide resources, recovers partial of failed transactions, and restores the system to
normal within a matter of microseconds.
Take the following picture as an example. The upper Vigor2960 is regarded as Master
(Active) device, the lower Vigor2960 is regarded as Slave (standby) device. When Master
Vigor2960 Series is broken down, the Slave device could replace the Master role to take
over all jobs as soon as possible. However, once the original Master is working again, the
Slave would be changed to original role to stand by.
i i l l i i t t y y
276
Vigor2960 Series User's Guide