Alteon Application Switch Operating System Application Guide
High Availability
576 Document ID: RDWR-ALOS-V2900_AG1302
After the request is sent, the timer routine is disabled with reset flag sfo_sync_req_flg.
• On the receipt of the sync message, the master invokes a response timer routine with one
second time interval.
After the master sends all the sessions to the backup, the total number of synced sessions are
logged with a syslog.
Service-based Session Failover (Session Mirroring) Limitations and
Recommendations
Limitations
• The feature is supported only in group-based active-standby and hot standby VRRP
configurations.
• The following filters and protocols are supported:
— SIP
— FTP (when ftpp is disabled under
cfg/slb/virt/service)
— Layer 4 SLB with delayed binding
— NAT filters
• The following filters and protocols are not supported:
— Active-active VRRP
— RTSP
— Layer 7 SLB
—
Allow/deny/redir filters
Recommendations
• Ensure a direct interswitch link between the master and backup, as NAAP packets cannot be
routed.
• The same priorities on all Alteons.
• Preemption enabled.
• Layer 4 switch port tracking enabled (
/cfg/l3/vrrp/vr/track/l4pts).
• A holdoff interval of at least 3 seconds (
/cfg/l3/vrrp/holdoff).
Service-Based Session Failover Commands
The following are commands that support this feature.
To enable and disable mirroring for a service
>> Main # /cfg/slb/virt <Virtual Server> /service <Service Number> / mirror
{enable|disable}