Configuring Route Health Injection

To specify the domain name resolve request, perform this task:

 

Command

Purpose

Step 1

 

 

Router(config)# ip slb probe probe-namedns

Configure an DNS probe and enter the tcp probe

 

 

submode1.

Step 2

Router(config-slb-probe-dns)# [expect

Configure times to wait between probes to make

 

failed interval retries receive]

a DNS connection, to receive a reply from the

 

 

server, and to limit the number of retries before

 

 

considering the real server as failed.

 

 

 

1.The no form of this command restores the defaults.

Configuring Route Health Injection

These sections describe the route health injection (RHI):

Understanding RHI, page 51

Configuring RHI for Virtual Servers, page 53

Understanding RHI

These sections describe the RHI:

RHI Overview, page 51

Routing to VIP Addresses Without RHI, page 52

Routing to VIP Addresses With RHI, page 52

Understanding How the CSM Determines VIP Availability, page 53

Understanding Propagation of VIP Availability Information, page 53

RHI Overview

RHI allows the CSM to advertise the availability of a VIP address throughout the network. Multiple CSM devices with identical VIP addresses and services can exist throughout the network. One CSM can override the load-balancing services over the other devices if the services are no longer available on the other devices, or one CSM can provide the services because it is logically closer to the client systems than other server load-balancing devices.

Note RHI is restricted to intranets because the CSM advertises the VIP address as a host-route and most routers do not propagate the host-route information to the Internet.

To enable RHI, configure the CSM to do the following:

Probe real servers and identify available virtual servers and VIP addresses

Advertise accurate VIP address availability information to the MSFC whenever a change occurs

 

 

Catalyst 6000 Family Content Switching Module Installation and Configuration Note

 

 

 

 

 

 

 

78-11631-02 Rev. A0

 

 

51

 

 

 

 

 

Page 51
Image 51
Cisco Systems 6000 manual Configuring Route Health Injection, Understanding RHI, RHI Overview