Splunk for F5 Networks LTM v11 iRule

I'm running version 9.4.8 and also trying to get f5 & Splunk to work. I tried creating the same iRule and I get the following error.

 

If I remove the HSL lines from the irule I can save the irule but when I apply it to a VIP I'm not seeing any traffic on Splunk at all.

 

 

01070151:3: Rule [Splunk] error:

 

line 36: [undefined procedure: HSL::open] [HSL::open -proto UDP -pool pool_syslog]

 

line 47: [undefined procedure: HSL::send] [HSL::send $hsl "<190>|$vhost|$client|$method|\"$url\"|HTTP/$http_version|$user_agent|\"$referer\"|$req_start_time|$req_length|$req_elapsed_time|$node|$status|$resp_start_time|$response_length|$virtual_server"]

 

 

 

If I remove the two lines that are causing the error I can save the iRule.

 

 

set hsl [HSL::open -proto UDP -pool pool_syslog]

 

 

HSL::send $hsl "<190>|$vhost|$client|$method|\"$url\"|HTTP/$http_version|$user_agent|\"$referer\"|$req_start_time|$req_length|$req_elapsed_time|$node|$status|$resp_start_time|$response_length|$virtual_server"