BIG IP LTM health monitor to be use source address as host name instead of interface self ip

[vadivelan]

our server team need to be white list the traffic logs based on the host name. but from F5 physical box taking self interface ip address as source for check the server health. 

is this possible to insert the hostname instead of self ip of the F5 interface while check the server health.

could you please share, if have any workaround to achieve the requirement 

[JRahm]

Hi @vadivelan, if you create a custom bash monitor, you could use curl and do whatever checking you want along with specifying a custom user agent (host header is destination, not source). Here's an example to get you started:

•  https://my.f5.com/manage/s/article/K31435017

[vadivelan]

Hi Jrahm,

Thanks for your reply. the actual requirement is our server team seeing lots of health monitor logs on the server logs, which is coming from F5 SLB source address is the self ip and source host name is null.

our server team required source host name in the header of the health monitor packet. we already create DNS A record for the self ip of the SLB. 

is there any workaround to include the source host name as well in the tcp header packet while send the health monitor from SLB to server.

[JRahm]

what kind of monitor are you using and what kind of server is it monitoring? 

[zamroni777]

there is no hostname field in tcp
https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure

if the application is http/s, you can add Host header in the monitor's send string.