Cisco PIX 525 Specifikace stáhnout pdf (Strana 146)

100

101

11-14

Cisco Security Appliance Command Line Configuration Guide

OL-6721-01

Chapter 11 Configuring Failover

Understanding Failover

• The user authentication (uauth) table.

• The routing tables.

• State information for Security Service Cards.

Note If failover occurs during an active Cisco IP SoftPhone session, the call will remain active because the

call session state information is replicated to the standby unit. When the call is terminated, the IP

SoftPhone client will lose connection with the Call Manager. This occurs because there is no session

information for the CTIQBE hangup message on the standby unit. When the IP SoftPhone client does

not receive a response back from the Call Manager within a certain time period, it considers the Call

Manager unreachable and unregisters itself.

Failover Health Monitoring

The security appliance monitors each unit for overall health and for interface health. See the following

sections for more information about how the security appliance performs tests to determine the state of

each unit:

• Unit Health Monitoring, page 11-14

• Interface Monitoring, page 11-14

Unit Health Monitoring

The security appliance determines the health of the other unit by monitoring the failover link. When a

unit does not receive hello messages on the failover link, then the unit sends an ARP request on all

interfaces, including the failover interface. The security appliance retries a user-configurable number of

times. The action the security appliance takes depends on the response from the other unit. See the

following possible actions:

• If the security appliance receives a response on any interface, then it does not fail over.

• If the security appliance does not receive a response on any interface, then the standby unit switches

to active mode and classifies the other unit as failed.

• If the security appliance does not receive a response on the failover link only, then the unit does not

failover. The failover link is marked as failed. You should restore the failover link as soon as possible

because the unit cannot fail over to the standby while the failover link is down.

Note If a failed unit does not recover and you believe it should not be failed, you can reset the state by entering

the failover reset command. If the failover condition persists, however, the unit will fail again.

Interface Monitoring

You can monitor up to 250 interfaces divided between all contexts. You should monitor important

interfaces, for example, you might configure one context to monitor a shared interface (because the

interface is shared, all contexts benefit from the monitoring).

1 2 ... 141 142 143 144 145 146 147 148 149 150 151 ... 603 604

Komentáře k této Příručce

Žádné komentáře

Cisco PIX 525 Specifikace Strana 146

Komentáře k této Příručce