Overriding Host Header in Health Monitor
By default,
Avi Load Balancer
appends additional HTTP headers (Host, User-Agent and Accept) into HTTP health monitor requests.The exact values of these headers are as follows:
For instance, if an admin (user) adds a Host header in
Header | Values |
|---|---|
User-Agent | avi/1.0\r\n |
Host | <hostname>\r\n |
Accept | */*;\r\n\r\n |
HTTP Client Request Header
field of a health monitor, Avi Load Balancer
will send this additional Host header together with the existing Host header (Host header inserted by Avi Load Balancer
).To prevent adding additional host headers, in the HTTP or HTTPS Health Monitors, select
Use Exact Request
in the Avi Load Balancer
UI.Alternatively, you can configure the health monitor to instruct
Avi Load Balancer
to pass the exact HTTP request string as specified by the admin (user), without any automatic insertion of the additional HTTP headers using the CLI.This indicates that user is now responsible for adding the appropriate headers to the HTTP client request field.
Configuration from Avi Load Balancer CLI
Avi Load Balancer
CLILogin to
Avi Load Balancer
CLI, and use configure healthmonitor System-HTTP
command to change the value of the flag exact-http-request
.[admin:10-1-1-1]: > configure healthmonitor System-HTTP [admin:10-1-1-1]: healthmonitor> http_monitor [admin:10-1-1-1]: healthmonitor:http_monitor> http_request [admin:10-1-1-1]: healthmonitor:http_monitor> http_request "HEAD / HTTP/1.0\r\n\r\n" Overwriting the previously entered value for http_request [admin:10-1-1-1]: healthmonitor:http_monitor> exact_http_request Overwriting the previously entered value for exact_http_request [admin:10-1-1-1]: healthmonitor:http_monitor> [admin:10-1-1-1]: healthmonitor:http_monitor> save [admin:10-1-1-1]: healthmonitor> save
Configuring through UI
Navigate to , click the edit icon to edit health monitors. Choose the desired HTTP health monitor, select the check box for
Use Exact Request
and click Save
.