Cabletron Systems SmartSwitch Router, Руководство пользователя

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Chapter 7: VRRP Configuration Guide
106 SmartSwitch Router User Reference Manual
ip-redundancy show
The ip-redundancy show command reports information about a VRRP configuration. To
display VRRP information, enter the following commands in Enable mode.
VRRP Configuration Notes
• The Master router sends keep-alive advertisements. The frequency of these keep-alive
advertisements is determined by setting the Advertisement interval parameter. The
default value is 1 second.
• If a Backup router doesn’t receive a keep-alive advertisement from the current Master
within a certain period of time, it will transition to the Master state and start sending
advertisements itself. The amount of time that a Backup router will wait before it
becomes the new Master is based on the following equation:
Master-down-interval = (3 * advertisement-interval) + skew-time
The skew-time depends on the Backup router's configured priority:
Skew-time = ( (256 - Priority) / 256 )
Therefore, the higher the priority, the faster a Backup router will detect that the Master
is down. For example:
– Default advertisement-interval = 1 second
– Default Backup router priority = 100
– Master-down-interval = time it takes a Backup to detect the Master is down
= (3 * adv-interval) + skew-time
= (3 * 1 second) + ((256 - 100) / 256)
= 3.6 seconds
• If a Master router is manually rebooted, or if its interface is manually brought down, it
will send a special keep-alive advertisement that lets the Backup routers know that a
new Master is needed immediately.
Display information about all
virtual routers. ip-redundancy show vrrp
Display information about all
virtual routers on a specified
interface. ip-redundancy show vrrp interface
<interface>
Display detailed statistics about
a specific virtual router ip-redundancy show vrrp
<vrid>
interface
<interface>
verbose