Overriding Host Header in Health Monitor
By default,
NSX Advanced 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
Header | Values |
|---|---|
User-Agent | avi/1.0\r\n |
Host | <hostname>\r\n |
Accept | */*;\r\n\r\n |
NSX Advanced Load Balancer
admin (user) adds a Host header in HTTP client request data field of a health monitor, NSX Advanced Load Balancer
will send this additional Host header together with the existing Host header (Host header inserted by NSX Advanced Load Balancer
).You can prevent from adding additional Host header. Use Exact Request option on
NSX Advanced Load Balancer
UI or use_exact_request flag in NSX Advanced Load Balancer
CLI for a health monitor instructs NSX Advanced Load Balancer
to pass the exact HTTP request string as specified by NSX Advanced Load Balancer
admin (user), without any automatic insertion of the additional HTTP headers. This indicates that user is now responsible for adding the appropriate headers to the HTTP client request field.Configuration from NSX Advanced Load Balancer CLI
NSX Advanced Load Balancer
CLILogin to
NSX Advanced 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
Configuration from NSX Advanced Load Balancer UI
NSX Advanced Load Balancer
UI- Navigate to .
- Choose the desired HTTP health monitor and clickediticon.
- Select the check box forUse Exact Request.
- ClickSave.