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Catalyst 6000 Family Content Switching Module Installation and Configuration Note
78-11631-02 Rev. A0
Configuring Route Health Injection

Understanding How the CSM Determines VIP Availability

For the CSM to determine if a VIP is available, you must configure a probe (HTTP, ICMP, Telnet, TCP,
FTP, SMTP, or DNS) and associate it with a server farm. With probes configured, the CSM performs
these checks:
•Probes all real servers on all server farms configured for probing
•Identifies server farms that are reachable (have at least one reachable real server)
•Identifies virtual servers that are reachable (have at least one reachable server farm)
•Identifies VIPs that are reachable (have at least one reachable virtual server)

Understanding Propagation of VIP Availability Information

With RHI, the CSM sends advertise messages to the MSFC containing the available VIP addresses. The
MSFC adds an entry in its routing table for each VIP address it receives from the CSM. The routing
protocol running on the MSFC sends routing table updates to other routers. When a VIP address becomes
unavailable, its route is no longer advertised, the entry times out, and the routing protocol propagates the
change.
Note For RHI to work on the CSM, the MSFC in the chassis in which the CSM resides must run Release
12.1.7(E) or later and must be configured as the client side router.
Configuring RHI for Virtual Servers
Step 1 Verify that you have configured VLANs (see the “Configuring VLANs” section on page2 1).
Step 2 Associate the probe with a server farm (see the “Configuring Server Farms” section on page24).
Step 3 Configure the CSM to probe real servers (see the “Configuring Probes for Health Monitoring” section
on page 46).
Step 4 Enter the advertise active SLB virtual server command to enable RHI for each virtual server:
Router(config)# ip slb vserver virtual_server_name
Router(config-slb-vserver)# advertise active
This example shows how to enable RHI for the virtual server named vserver1.
Router(config)# ip slb vserver vserver1
Router(config-slb-vserver)# advertise active