iRule to ping host

when HTTP_RESPONSE {
 HTTP::header insert Via "[LB::server addr]"
 You could also replace the Server header if it is present
 }

when LB_SELECTED {
 set whichserver [LB::server addr]
 }
when HTTP_REQUEST {
 if { string tolower [HTTP::uri] equals "/whichserver" } {
  HTTP::respond 200 content "Real server IP is: $whichserver" noserver Content-Type
  "text/html" Connection "Close"
  Stop processing the iRule for this event here
  return }
 }

Thanks Steve. I can see where those would be helpful, however the HTTP tools look like they would cost us, as the free version limits the number of sites. Using "ping" would be free :) If there is an iRule that will accomplish responding with the host IP from the client workstation when it pings the site being load balanced. Our Sharepoint admin says he was initially seeing pings of the host IP addresses in the pool, rather than the virtual IP address of the pool for the Sharepoint site, when he would ping from a client. I've not changed a setting, so is there some setting on the load-balance, via i-Rule or otherwise that would make this work?

I would like to send a txt message to my unix team when I hit LB_FAILED messages in /var/log/tmm (Only when no nodes available) Any help is appreciatedis remote log command (in irule) or custom syslog-ng usable? Colin and Deb have written great articles about logging and syslog-ng as following. 

The101: iRules 101 - Logging & Comments by Colin

https://devcentral.f5.com/s/articles/the101-irules-101-logging-amp-comments

LTM 9.4.2+: Custom Syslog Configuration by Deb 

https://devcentral.f5.com/s/articles/LTM-9-4-2-Custom-Syslog-Configuration

Thanks all. I'll look closer at the HTTP header tools. The one had a free version, but said it was limited to the number of sites you could configure to use it (as I understood what I read), and potentially we will eventually have a large number of sites. Also, it requires an install on the client workstation, and I think our application guys are wanting something that is quickly reviewable.

I'll look at the forwarding information.

In the meantime I've been looking at iRules and found one that perhaps I could adapt to just log the information on the load balance system log. The iRule below is not complete though. I'd like to set up each iRule for the Sharepoint Sites only that we load balance, and don't know how to do that. Basically I'd like each time someone connects to a load balanced Sharepoint site virtual IP address pool that the client's IP address and the address of the physical host server gets logged as an informational message in the F5 logs. I think the iRule below will work, except I'm still researching how to only use the rule for Sharepoint sites. I figure there is a rule where I can say if a "CLIENT ACCEPTED" occurs to a specific vip, but potentially we will have dozens of VIPs in the future, so I could have a lot of iRules to manage. Is there a way to look at Client Accepted connections for only a type of pool? We're using the Sharepoint templates.

rule SharePoint_sitename{

Whoops forgot the ending brackets:

rule SharePoint_sitename{