Response Code: 404

Hi Expert

Im getting following message in my virtual F5 ltm. I have three IIS node node in the pool and im getting random number of error message like below. Can anyone let me know why im getting error 301/404/500/503?

Jan 23 10:35:42 f5 notice mcpd[7153]: 01070638:5: Pool /Common/CRM-Member member /Common/CRM-WEB-03:443 monitor status down. [ /Common/http_monitor_aliase_80: down; last error: /Common/http_monitor_aliase_80: Response Code: 301 (Moved Permanently); Response Code: 404 (Not Found); No successful responses received before deadline.; Unable to connect; Response Code: 500 (Internal Server Error); Response Code: 503 (Service Unavailable) @2018/01/23 10:35:42. ] [ was up for 0hr:0min:22sec ]

Jan 23 10:35:46 f5 notice mcpd[7153]: 01070727:5: Pool /Common/CRM-Member member /Common/CRM-WEB-03:443 monitor status up. [ /Common/http_monitor_aliase_80: up ] [ was down for 0hr:0min:4sec ]