rlm_ippool performance

[Santosh]

Hi

I have a radius test client which can generate 1000's of radius access  
request in a single second. These radius clients need an IP address.  
So, I configured local ip ppol to assign ip addresses. When I run the  
tests I could see that I can scale up at the rate of 5 per second. If  
I increase the client access rate I run into following issue. I am  
guessing rlm_ippool is unable to handle so many requests.

 From Radius.log

Error: WARNING: Unresponsive child for request 282, in module  
main_pool1 component post-auth

The question here is will rlm_ippool be able to give away ip addresses  
to 100's of clients per second? or do I need to look at some thing  
else? Please suggest.

Thanks, Santosh

modules/ippool file

ippool main_pool1 {

              range-start = 20.0.1.1
              range-stop = 20.0.254.254
              netmask = 255.255.0.0
              cache-size = 64000
              session-db = ${db_dir}/db.ippool
	     ip-index = ${db_dir}/db.ipindex
	     override = yes
              maximum-timeout = 0
             #key = "%{NAS-IP-Address} %{NAS-Port}"
     }

users file :

sant            Cleartext-Password := "sant", Pool-Name := "main_pool1"
                      Fall-Through = Yes,
                      Group = "test1",

/sites-enabled/default

post-auth {
	main_pool1
	exec
	Post-Auth-Type REJECT {
                  attr_filter.access_reject
         }
}