Cisco Support Community
Community Member

ACL Sticky problem

Dear Expert,

I'm looking to get your help on the following

we have load balancer configuired to use hach address  with source IP stickiness, but it is not working fine

most of the request are going to one server and the other servers are free.

my questions is

if i want to use least connection load balncing algorithim , the sticky can be achieved or not?

Thanks in advance


Cisco Employee

Re: ACL Sticky problem

In loadbalancing world, there are 2 things to not mismatch.

First, the loadbalancing algorithm.

Then the sticky method.

Some loadbalancing alogorithm may result in some form of stickyness. For example  the hash method.

The problem has you could figure out is that the algorithm is not designed to spread the load evenly accross all servers.

So, what you have to do is select a loadbalancing algorithm and then select a stichy method.

In your case, you could use 'predictor leastconn' and use a sticky method based on source ip address.

Here is how to configure the sticky group.

sticky ip-netmask address source RESERVATIONS_STICKY
  timeout 20
  replicate sticky
  serverfarm linux1-80

You then need to use the sticky group in your policy instead of using the serverfarm.


Community Member

Re: ACL Sticky problem

Dear Gilles,

Thanks a lot for your reply, and please accept my excuse because I'm not a network guy

I have asked the same question to our load balancer administrator and as understood from him "It is not possible to use stickiness method with the leastconn predictor". So please if you have any document or reference to show it to him.

Also do you think the load distribution will be enhanced if we used the least conn predictor?



Cisco Employee

Re: ACL Sticky problem

It is possible to use stickyness and leastconn.

There is nothing to prevent this configuration.

However, that does not mean you will have better loadbalancing results since eventually you want stickyness so, if one person opens many more connections that the other ones, you will see more hits on one server.

I would suggest to give it a try.

Try leastconn + stickyness or roundrobin + stickyness...

There is no perfect combination that would work for all.

You have to try all possible combinations and see which one is best for you.


Community Member

Re: ACL Sticky problem

Dear Gilles,

Thanks for your helpful support,

I will do a try and I will update you

Thanks again,


CreatePlease to create content