Design Help-> Persistance Rebalance in ACE

Unanswered Question
Jul 11th, 2010


I need one suggestion from you.

I have 2 servers that need to be load balanced.

Real Server 1 IP Address:

Realo Server 2 IP Address:


My requirement is: Real Server will raise request (loopback request as per Oracle Guys) towards the VIP. VIP will handover the request to the same server from where the original request was made.

Real Server 1--> Request--> VIP-->Real Server 1

Real Server 2--> Request--> VIP-->Real Server 2

Is this possible? If Yes, then whether some thing to be configured on ACE??

Kindly suggest..

I have this problem too.
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Sean Merrow Mon, 07/12/2010 - 07:19


Yes, you can do this.  See example below:

  • Clients coming in on VLAN 251 connect to the VIP and are load balanced without source NAT.
  • Servers connecting to the VIP on VLAN 451 are load balanced AND source NAT'd because they match both class-maps.

access-list ANYONE line 10 extended permit ip any any

rserver host SERVER_01
  ip address
rserver host SERVER_02
  ip address
rserver host SERVER_03
  ip address

serverfarm host REAL_SERVERS
  rserver SERVER_01
  rserver SERVER_02
  rserver SERVER_03

class-map match-all REAL_SERVERS
  2 match source-address

class-map match-all VIP-30
  2 match virtual-address tcp eq www

policy-map type loadbalance first-match SLB_LOGIC
  class class-default
    serverfarm REAL_SERVERS

policy-map multi-match CLIENT_VIPS
  class VIP-30
    loadbalance vip inservice
    loadbalance policy SLB_LOGIC
    loadbalance vip icmp-reply active
    nat dynamic 1 vlan 451

interface vlan 251
  description Client vlan
  ip address
  access-group input ANYONE
  service-policy input REMOTE_MGT
  service-policy input CLIENT_VIPS
  no shutdown
interface vlan 451
  description Servers vlan
  ip address
  access-group input ANYONE
  service-policy input CLIENT_VIPS
nat-pool 1 netmask pat
  no shutdown

ip route

Hope this helps,


acharyr123 Mon, 07/12/2010 - 22:32

Thanks Sean for your reply. But my requirement is different:

Let me furnish my requirements:

2-3 Oracle Instances (Oracle 10G) are installed on same Server. There are 2 servers.

Server 1 will raise Loopback request to the ACE VIP & VIP will return back the same request to Server 1

Server 2 will raise Loopback request to the ACE VIP & VIP will return back the same request to Server 2.

Do u suggest something to be done in ACE for such scenario??

Kindly suggest.



Sean Merrow Tue, 07/13/2010 - 14:05

Sure, you can still use the config I gave you and modify it a bit.  You can put each server in its own serverfarm.  Then you can load balance to its own serverfarm based on the source-ip address.  With the example I provided, i'm using source-ip to do source NAT.  In your case you would use source-ip to do NAT and to load balance to the serverfarm that the server resides.

Make sense?



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