8-52

User

Guide

for

the

Cisco

Application

Networking

Manager

5.2

OL-26572-01

Chapter

8

Configuring

Real

Servers

and

Server

Farms

Configuring

Health

Monitoring

FTP

Initiates

an

FTP

session.

By

default,

this

probe

is

for

an

anonymous

login

with

the

option

of

configuring

a

user

ID

and

password.

The

ACE

performs

an

FTP

GET

or

LS

to

determine

the

outcome

of

the

problem.

This

probe

supports

only

active

connections.

HTTP

Sets

up

a

TCP

connection

and

issues

an

HTTP

request.

Any

valid

HTTP

response

causes

the

probe

to

mark

the

real

server

as

passed.

HTTPS

Similar

to

an

HTTP

probe,

but

this

probe

uses

SSL

to

generate

encrypted

data.

ICMP

Sends

an

ICMP

request

and

listens

for

a

response.

If

the

server

returns

a

response,

the

ACE

marks

the

real

server

as

passed.

If

there

is

no

response

and

times

out,

or

an

ICMP

standard

error

occurs,

such

as

DESTINATION_UNREACHABLE,

the

ACE

marks

the

real

server

as

failed.

IMAP

Initiates

an

IMAP

session,

using

a

configured

user

ID

and

password.

Then,

the

probe

attempts

to

retrieve

email

from

the

server

and

validates

the

result

of

the

probe

based

on

the

return

codes

received

from

the

server.

POP

Initiates

a

POP

session,

using

a

configured

user

ID

and

password.

Then,

the

pr

obe

attempts

to

retrieve

email

from

the

server

and

validates

the

result

of

the

probe

based

on

the

return

codes

received

from

the

server.

RADIUS

Connects

to

a

RADIUS

server

and

logs

into

it

to

determine

if

the

server

is

up.

RT

S

P

Establishes

a

TCP

connection

and

sends

a

request

packet

to

the

server.

The

ACE

compares

the

response

with

the

configured

response

code

to

determine

whether

the

probe

succeeded.

Scripted

Executes

probes

from

a

configured

script

to

perform

health

probing.

This

method

allows

you

to

author

specific

scripts

with

features

not

present

in

standard

probes.

For

ACE

appliances,

the

script

probe

filename

must

first

be

established

on

the

device.

SIP-TCP

Establishes

a

TCP

connection

and

sends

an

OPTIONS

request

packet

to

the

user

agent

on

the

server.

The

ACE

compares

the

response

with

the

configured

response

code

or

expected

string,

or

both,

to

determine

whether

the

probe

has

succeeded.

If

you

do

not

configure

an

expected

status

code,

any

response

from

the

server

is

marked

as

failed.

SIP-UDP

Establishes

a

UDP

connection

and

sends

an

OPTIONS

request

packet

to

the

user

agent

on

the

server.

The

ACE

compares

the

response

with

the

configured

response

code

or

expected

string,

or

both,

to

determine

whether

the

probe

has

succeeded.

If

you

do

not

configure

an

expected

status

code,

any

response

from

the

server

is

marked

as

failed.

SMTP

Initiates

an

SMTP

session

by

logging

into

the

server.

SNMP

Establishes

a

UDP

connection

and

sends

a

maximum

of

eight

SMNP

OID

queries

to

probe

the

server.

The

ACE

weighs

and

averages

the

load

information

that

is

retrieved

and

uses

it

as

input

to

the

least-loaded

algorithm

for

load-balancing

decisions.

If

the

retrieved

value

is

within

the

configured

threshold,

the

server

is

marked

as

passed.

If

the

threshold

is

exceeded,

the

server

is

marked

as

failed.

TCP

Initiates

a

TCP

handshake

and

expects

a

response.

By

de

fault,

a

successful

response

causes

the

pr

obe

to

mark

the

server

as

pa

ssed.

The

probe

then

sends

a

FIN

t

o

end

the

sessi

on.

If

the

response

i

s

not

valid,

or

if

there

is

no

response,

the

probe

marks

the

real

server

as

failed.

TELNET

Establishes

a

connection

to

the

real

server

and

verifies

that

a

greeting

from

the

application

was

received.

Table

8-11

Probe

Types

(continued)

Probe

Type

Description