7-44
User
Guide

for

the

Cisco

Application

Networking

Manager

5.2
OL-26572-01
Chapter
7






Configuring

Virtual

Servers
Configuring
Virtual

Servers
Hash
Layer

4
Method
that

indicates

that

the

ACE

is

to

select

the

server

by

using

a

Layer

4

generic

protocol
load-balancing
method.

Use

this

predictor

to

load

balance

packets

from

protocols

that

are

not

explicitly
supported
by

the

ACE.
a.
In
the

Begin

Pattern

field,

enter

the

beginning

pattern

of

the

Layer

4

payload

and

the

pattern
string
to
match

before

hashing.

If

you

do

not

specify

a

beginning

pattern,

the

ACE

starts

parsing

the

HTTP
body
immediate

following

the

offset

byte.

You

cannot

configure

different

beginning

and

ending
patterns
for

different

server

farms

that

are

part

of

the

same

traffic

classification.
Valid
entries

are

unquoted

text

strings

with

no

spaces

and

a

maximum

of

255

alphanumeric
characters.
The

ACE

supports

regular

expressions

for

matching

string

expressions.

Ta

b

l

e


14-33
lists
the

supported

characters

that

you

can

use

for


matching

string

expressions.
b.
In
the
End
Pattern
field,
enter

the

pattern

that

marks

the

end

of

hashing.
If
you

do

not

specify

either
a
length

or

an

end

pattern,

the

ACE

continues

to

parse

the

data

until

it

reaches

the

end

of

the

field
or
the

end

of

the

packet,

or

until

it

reaches

the

maximum

body

parse

length.

You

cannot

configure
different
beginning

and

ending

patterns

for


different

server

farms

that

ar

e

part

of

t

he

same

traffic
classification.
Valid
entries

are

unquoted

text

strings

with

no

spaces

and

a

maximum

of

255

alphanumeric
characters.
The

ACE

supports

regular

expressions

for

matching

string

expressions.

Ta

b

l

e


14-33
lists
the

supported

characters

that

you

can

use

for


matching

string

expressions.
c.
In
the

Length

(Bytes)

field,

enter

the
length

in

bytes

of

the

portion

of

the

payload

(starting

with

the
byte
after

the

offset

value)

that

the

ACE

uses

for

sticking

the

client

to

the

server.

Valid

entries

are
from
1

to

1000

bytes.
The
offset

and

length

can

vary

from

0

to

1000

bytes.

If

the

payload

is

longer

than

the

offset

but
shorter
than

the

offset

plus

the

length

of

the

payload,

the

ACE

sticks

the

connection

based

on

that
portion
of

the

payload

starting

with

the

byte

after

the

offset

value

and

ending

with

the

byte

specified
by
the

offset

plus

the

length.

The

total

of

the

offset

and

the

length

cannot

exceed

1000.
Note
You
cannot
specify

both

t

he

l

ength

and

end-pattern

opt

ions

for

a

Hash

Layer
4
pr

edictor.
d.
In
the

HTTP

Content

Offset

(Bytes)
field,
enter
the

portion

of
the

content

that

the

ACE

uses

to

stick
the
client

on

a

particular

server

by

indicating

the

bytes

to

ignore

starting

with

the

first

byte

of

the
payload.
Valid

entries

are

from

0

to

999

bytes.

The

default

is

0,

which

indicates

that

the

ACE

does
not
exclude

any

por

tion

of

t

he

content.
Hash
URL
Method
that

indicates

that

the

ACE

is

to

select

the

server

using

a

hash

value

based

on

the

URL.

Use

this
method
to

load

balance

firewalls.
Enter
values

in

one

or

both

of

the

pattern

fields:

•
In
the

URL

Begin

Pattern

field,
enter
the

beginning

pattern

of

the
URL
and

the

pattern

string

to
parse.

•
In
the

URL

End

Pattern

field,

enter
the
ending
pattern

of

the

URL

and

the

pattern

string
to
parse.
Valid
entries

for

t

hese

fields

ar

e

unquoted

t

ext

st

rings

with

no

spaces

and

a

maximum

of

255
alphanumeric
characters

for

each

pattern

you

configure.
Table
7-14
Predictor
Methods

and

Attributes

(continued)