Load balance on source ip address

Hoolio wrote something up for SNATing based on the 3rd Octet...that logic could easily be ported over...if I find time today, I'll try writing something up

http://devcentral.f5.com/Forums/tabid/1082223/asg/52/showtab/groupforums/afv/topic/aff/31/aft/813179/Default.aspx

 
  when CLIENT_ACCEPTED {  
    
      Use a local array to configure the 5 SNAT addresses  
     set snat_ips(0) 1.1.1.1  
     set snat_ips(1) 2.2.2.2  
     set snat_ips(2) 3.3.3.3  
     set snat_ips(3) 4.4.4.4  
     set snat_ips(4) 5.5.5.5  
    
      Use getfield to parse the third octet from the client IP address  
      Get the modulus of the third octet against the number of the SNAT IPs in the array  
     set snat_number [expr {[getfield [IP::client_addr] "." 3] % [array size snat_ips]}]  
     log local0. "Client IP: [IP::client_addr], SNAT number $snat_number, SNAT IP: $snat_ips($snat_number)"  
    
      Apply the SNAT  
     snat $snat_ips($snat_number)  
  }  
  

Quick mod....test it out and see whether it works for you...I pretty much just did find and replace so I very well may have missed something.

  when HTTP_REQUEST {  
    
      Use a local array to configure the 4 pools 
     set pool_choice(0) pool_1 
     set pool_choice(1) pool_2 
     set pool_choice(2) pool_3 
     set pool_choice(3) pool_4 
     
    
      Use getfield to parse the third octet from the client IP address  
      Get the modulus of the third octet against the pool members in the array  
     set pool_number [expr {[getfield [IP::client_addr] "." 3] % [array size pool_choice]}]  
     log local0. "Client IP: [IP::client_addr], Pool number $pool_number, Pool Choice: $pool_choice($pool_choice)"  
    
      choose a pool
     pool $pool_choice($pool_number)  
  }  

Chris -

 

 

Thank you for the quick reply! We are not currently using SNAT and I am not sure I want to change what is currently working...

 

 

What do you think about this which I modified from this http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/108/iRules-Optimization-101--01--if-elseif-and-switch.aspx

 

 

I believe that this will route an traffic with the IP address ending in 1 or 2 to pool_1 and any traffic with the IP address ending in 3 or 4 to pool_2 and so on.

 

when CLIENT_ACCEPTED {

 

Determine which pool based on last digit of Clinet IP Address

 

switch -regexp [IP::client_addr ] {

 

".*[1,2]$" { pool pool_1 }

 

".*[3,4]$" { pool pool_2 }

 

".*[5,6]$" { pool pool_3 }

 

".*[7,8]$" { pool pool_4 }

 

".*[9,0]$" { pool pool_5 }

 

}

 

}

 

 

Thanks

 

Hi Dan,

 

I would avoid using regex. Another method is to use lindex and split tcl commands

 

 

 

when CLIENT_ACCEPTED {

 

set ip4 [lindex [split [IP::client_addr] "."] 3]

 

if { ($ip4 >= 0) and ($ip4 < 65) } {

 

pool pool_1

 

} else if { ($ip4 >= 65) and ($ip4 < 129) } {

 

pool pool_2

 

} else if { ($ip4 >= 129) and ($ip4 < 193) } {

 

pool pool_3

 

} else if { ($ip4 >= 193) and ($ip4 < 256) } {

 

pool pool_4

 

}

 

}

 

 

 

This is untested of course

 

 

I hope this helps

 

 

Bhattman

Bhattman -

 

 

Thank you for the reply. Might I ask why you are against regular expressions?

 

Hi Dan,

 

I'm actually not against it's use, but avoid it all costs because Regular expressions are very CPU intensive. It would certainly be the only option I would use if I can't find another method.

 

 

Bhattman