Document ID: RDWR-ALOS-V2900_AG1302
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Chapter 18 – Health Checking
Health checking allows you to verify content accessibility in large Web sites. As content grows and
information is distributed across different server farms, flexible, customizable content health checks
are critical to ensure end-to-end availability.
The following health-checking topics are described in this chapter:
•
Understanding Health Check Monitoring, page 482
—Describes the use of template health checks
and reusable health checks, and how to assign them to real servers and groups.
•
Supported Health Check Types, page 484
—Lists all the supported health check types available:
—
—Describes how to perform Layer 1 health checking on an
Intrusion Detection Server (IDS).
—
—TCP health checks help verify the TCP applications that
cannot be scripted.
—
—UDP health checks help verify the UDP applications that
cannot be scripted.
—
—Explains how ICMP health checks are used for UDP
services.
—
HTTP/S Health Checks, page 486
—Provides examples of HTTP-based health checks using
hostnames.
—
TCP and UDP-based DNS Health Checks, page 488
—Explains the functionality of the DNS
Health Checks using UDP packets.
—
—Explains how to health check a real server using the TFTP
protocol.
—
—Explains how to perform SNMP health checks to real servers
running SNMP Agents.
—
FTP Server Health Checks, page 489
—Describes how the File Transfer Protocol (FTP) server
is used to perform health checks and explains how to configure Alteon to perform FTP health
checks.
—
POP3 Server Health Checks, page 489
—Explains how to use Post Office Protocol Version 3
(POP3) mail server to perform health checks between a client system and a mail server and
how to configure Alteon for POP3 health checks.
—
SMTP Server Health Checks, page 490
—Explains how to use Simple Mail Transfer Protocol
(SMTP) mail server to perform health checks between a client system and a mail server and
how to configure Alteon for SMTP health checks.
—
IMAP Server Health Checks, page 490
—Describes how the mail server Internet Message
Access Protocol (IMAP) protocol is used to perform health checks between a client system
and a mail server.
—
NNTP Server Health Checks, page 490
—Explains how to use Network News Transfer
Protocol (NNTP) server to perform health checks between a client system and a mail server
and how to configure Alteon for NNTP health checks
—
RADIUS Server Health Checks, page 490
—Explains how the RADIUS protocol is used to
authenticate dial-up users to Remote Access Servers (RASs).
—
SSL HELLO Health Checks, page 491
—Explains how Alteon queries the health of the SSL
servers by sending an SSL client “Hello” packet and then verifies the contents of the server's
“Hello” response.
—
WAP Gateway Health Checks, page 491
—Discusses how Alteon provides connection-less
and connection-oriented WSP health check for WAP gateways.
—
LDAP/LDAPS Health Checks, page 492
—Describes how to configure Alteon to perform
Lightweight Directory Access Protocol (LDAP) health checks for Alteon to determine if the
LDAP server is running.