When host-update is enabled in session accounting, a dual-stack subscriber can generate multiple host update accounting messages at the start and end of a session (for example, one for the IPv4 host and two more for the IPv6 WAN and IPv6 PD hosts). Two features can be used to reduce the number of host update messages per subscriber.
The first feature delays the Start Accounting message by a configurable value and is applicable to both PPPoE and IPoE sessions. The command for configuring this feature is config>subscr-mgmt>acct-plcy>delay-start-time. The delay allows the full dual-stack address assignment to be completed before triggering the accounting Start message. The Start message reports all the addresses and prefixes assigned to the subscriber at that time. Subsequent new or disconnected hosts triggers interim host updates if enabled.
The second feature is for PPPoE sessions only and is used to reduce the number of host update messages when a dual-stack PPP subscriber disconnects. The command for configuring this feature is config>subscr-mgmt>sub-prof>rad-acct>session-optimized-stop. A single accounting Stop message containing all the addresses and prefixes for the subscriber at the time is generated.