7-6
User
Guide

for

the

Cisco

Application

Networking

Manager

5.2
OL-26572-01
Chapter
7






Configuring

Virtual

Servers
Configuring
Virtual

Servers
Virtual
Server

Testing

and

Troubleshooting
As
outlined

in

the

“Virtual

Server

Usage

Guidelines”

section

on

page

7-5 ,

first

set

up

a

basic

virtual
server
that

onl

y

enables

connectivity

and

si

mple

load

balancing,

such

as

rou

nd-robin

between

two

real
servers.
Next,

use

a

client,

such

as

a

web

browser,

to

send

a

request

from

the

client

network

to

the

virtual
server's
VIP

address.

If

the

request

is

successful,

you

can

now

make

changes

or

add

virtual

server
features.
If
the

request

is

not

successful,

begin

virtual

server

troubleshooting

as

outlined

in

the

following
sequence:
1.
Wait
and
retry
your
request
after
a
minute

or

two,

especially

if

the

existing
ACE
configuration
is
large.
It

can

take

seconds

or

even

minutes

for

configuration

changes

to

affect

how

traffic

is

handled
by
ACE.
2.
Click
the
Details
button
in

the

lower

right
of
the

Virtual

Server

page.
The
Details
button
displays
the
output

of

the

show

service-policy

CLI

command.
3.
Verify
that
th

e

VIP

State

i

n
the
show
service-policy
CLI

command

out

put

i

s
INSERVICE.
If

t

he
VIP
state

is

not

INSERVICE,

this

may

indicate

the

following:

–

The

virtual

server

has

been

manually

disabled

in

the

configuration.

–

The

real

servers

are

all

unreachable

from

ACE

or

manually

disabled.

If

all

of

a

virtual

server's
real
servers

are

out

of

service

due

to

one

of

those

reasons,

the

virtual

server

itself

will

be

marked
Out
Of

Service.
4.
Verify
the

Hit

Count

in

the
show
service-policy

CLI

command

output.

Hit

Count
shows

the

number
of
requests

received

by

ACE.

This

value

should

increase

for

each

request

attempted

by

your

client.
If
the

hit

count

does

not

increase

with

each

request,

this

indicates

that

the

request

is

not

reaching
your
virtual

server

configuration.
This
could

be

a

problem

with:

–

A

physical

connection.

–

VLAN

or

VLAN

interface

configuration.

–

Missing

or

incorrect

ACL

applied

to

the

client

interface.

–

Incorrect

IP

address

(that

is,

a

VIP

that

is

not

valid

on

the

selected

VLANs

for

the

virtual

server,
or
a

VIP

that

is

not

accessible

to

your

client).
If
the

Hit

Count

value

increases

but

no

response

is

received

(Server

Pkt

Count

does

not

increases),
the
problem

is

more

likely

to

be

in

the

connectivity

between

the

ACE

and

the

backend

real

servers.
This
issue

is

t

ypically

caused

by

one

or

mo

re

of

the

fol

lowing

pr

oblems:

–

You

ar

e

working

on

a

on

e-armed

configuration

(t

hat

is,

do

not

plan

t

o

change

routing

for


your
real
servers)

and

have

not

selected

an

appropriate

NAT

pool

for

your

virtual

server

to

use

with
source
NAT.

–

A

different

routing

problem

(f

or

example,

server

traffic

does

not


know

how

t

o

get

back

to

the
AC
E

)

.

–

Addressing

problem

(for

example,

you

have

an

incorrect

real

server

address,

or

the

real

server
is
not

accessible

to

ACE

due

to

network

topology).
Note
Hit
count

can

increase

by

more

than

one,
even
if
you
make

only

a

single

request

from

your

web
browser,
because

retrieving

a

typical

web

page

makes

many

requests

from

the

client

to

the

server.