H3C S6850 Series Configuration Guide

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3. Enable the short DRCP timeout timer.
drni drcp period short
By default, an interface uses the long DRCP timeout timer (90 seconds).
Setting the keepalive hold timer for identifying the
cause of IPL down events
About the keepalive hold timer
The keepalive hold timer starts when the IPL goes down. The keepalive hold timer specifies the
amount of time that the device uses to identify the cause of an IPL down event.
• If the device receives keepalive packets from the DR peer before the timer expires, the IPL is
down because the IPL fails.
• If the device does not receive keepalive packets from the DR peer before the timer expires, the
IPL is down because the peer DR device fails.
Restrictions and guidelines
For the DR member device to correctly determine the cause of an IPL down event, make sure the
keepalive hold timer is longer than the keepalive interval and is shorter than the keepalive timeout
timer.
If you use DRNI and VRRP together, make sure the keepalive hold timer is shorter than the interval
at which the VRRP master sends VRRP advertisements. Violation of this restriction might cause a
VRRP master/backup switchover to occur before IPL failure is confirmed. To set the interval at which
the VRRP master sends VRRP advertisements, use the
vrrp vrid timer advertise
command. For more information about this command, see High Availability Command Reference.
Procedure
1. Enter system view.
system-view
2. Set the keepalive hold timer.
drni keepalive hold-time value
By default, the keepalive hold timer is 3 seconds.
Configuring DR system auto-recovery
About DR system auto-recovery
If only one DR member device recovers after the entire DR system reboots, auto-recovery enables
that member device to remove its DR interfaces from the DRNI DOWN interface list.
• If that member device has up DR interfaces, it takes over the primary role when the reload delay
timer expires and forwards traffic.
• If that member device does not have up DR interfaces, it is stuck in the None role and does not
forward traffic.
If auto-recovery is disabled, that DR member device will be stuck in the None role with all its DR
interfaces being DRNI DOWN after it recovers.
Restrictions and guidelines
If both DR member devices recover and have up DR interfaces after the entire DR system reboots,
active-active situation might occur if both IPL and keepalive links were down when the reload delay
timer expires. If this rare situation occurs, examine the IPL and keepalive links and restore them.

H3C S6850 Series Specifications

General

Brand	H3C
Model	S6850 Series
Category	Switch
Language	English