Cisco WS-X6708-10G-3CXL= - 10 Gigabit Ethernet Module Manual de usuario descargar pdf (Pagina 52)

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Recovery from Dual-Active Scenario

If a VSL flap occurs, the system recovers automatically. Upon a link-up event from any of the VSL links, the previous

active supervisor engine that is now in recovery mode reloads itself, allowing it to initialize as the hot-standby

supervisor engine. If the peer chassis is not detected because the VSL is down again, the dual-active detection

mechanism determines whether or not the peer chassis is active. If the peer chassis is detected, this event is treated

as another VSL failure event and the chassis once again enters into recovery mode.

When the VSL is restored, the following messages are displayed on the console and the switch in recovery mode

(previous active virtual switch) reloads:

*Jun 26 16:23:34.877: %DUALACTIVE-1-VSL_RECOVERED: VSL has recovered during dual-

active situation: Reloading switch 1

*Jun 26 16:23:34.909: %SYS-5-RELOAD: Reload requested Reload Reason: Reload Command.

<…snip…>

***

*** --- SHUTDOWN NOW ---

***

*Jun 26 16:23:42.012: %SYS-SW1_SP-5-RELOAD: Reload requested

*Jun 26 16:23:42.016: %OIR-SW1_SP-6-CONSOLE: Changing console ownership to switch

processor

*Jun 26 16:23:42.044: %SYS-SW1_SP-3-LOGGER_FLUSHED: System was paused for 00:00:00 to

ensure console debugging output.

System Bootstrap, Version 8.5(1)

<…snip…>

After the chassis reloads, it reinitializes and the supervisor engine enters into standby virtual switch mode. If Switch

Preemption is configured to prioritize this chassis to become active, it assumes this role after the preempt timer

expires.

Finally, traffic convergence associated with a VSL failure scenario involves the dual-active detection mechanisms, the

recovery mode operations and finally the restoration period which involves a reload of the previously active VSS

chassis. In each one of the three previous stages there is a possibility for some traffic disruption. Typically the

disruption will be similar to the NSF/SSO switchover scenarios described previously but other factors from the overall

network design can have an effect as well. These include the types of connections to the VSS, either L2 or L3

Multichassis Etherchannels or Equal Cost Paths. For more detailed analysis on convergence times associated with

the VSS failure scenarios please refer to following document:

Campus 3.0 Virtual Switching System Design Guide

http://www.cisco.com/en/US/docs/solutions/Enterprise/Campus/VSS30dg/campusVSS_DG.html

Quality of Service

Quality of service (QoS) handling on the Cisco Catalyst 6500 Series Switches can be separated into two distinct

areas of responsibility: port-based QoS features and forwarding-engine (PFC or DFC) features. Both areas operate

together to make sure of differentiated servicing of traffic throughout the system.

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Cisco WS-X6708-10G-3CXL= - 10 Gigabit Ethernet Module Manual de usuario Pagina 52