Inbound REST call for alm_hardware table fails with 401 response codeSummaryWhen a API call is received by Servicenow to retrieve data from the target tables in the instance, the request fails and returns 401 response code. The same API calls works fine when tested from REST API explorer in the Servicenow instance. The application logs indicate below warning in the logs : 2021-03-24 02:34:56 (459) API_INT-thread-3 SYSTEM txid=46ad205edb43 DEBUG: #243316 [REST API] RESTAPIProcessor : Started initializing REST Request2021-03-24 02:34:56 (459) API_INT-thread-3 SYSTEM txid=46ad205edb43 DEBUG: #243316 [REST API] URIHandler : Resolving URI: /now/table/alm_hardware2021-03-24 02:34:56 (459) API_INT-thread-3 SYSTEM txid=46ad205edb43 DEBUG: #243316 [REST API] RESTAPIProcessor : URI Resolving Duration duration_micro_secs=682021-03-24 02:34:56 (459) API_INT-thread-3 SYSTEM txid=46ad205edb43 User agent with HTTP/1.1 and no encoding: Mozilla/5.0 (Windows NT; Windows NT 10.0; en-AE) WindowsPowerShell/5.1.19041.6102021-03-24 02:34:56 (459) API_INT-thread-3 SYSTEM txid=46ad205edb43 DEBUG: #243316 [REST API] RESTAPIProcessor : Finished initializing REST Request2021-03-24 02:34:56 (464) API_INT-thread-3 SYSTEM txid=46ad205edb43 WARNING *** WARNING *** Required HTTP authorization header (Authorization) not present2021-03-24 02:34:56 (464) API_INT-thread-3 SYSTEM txid=46ad205edb43 #243316 [REST API] RESTAPIProcessor : User Not Authenticated2021-03-24 02:34:56 (464) API_INT-thread-3 SYSTEM txid=46ad205edb43 DEBUG: #243316 [REST API] RESTAPIProcessor : End of Request Processing2021-03-24 02:34:56 (464) API_INT-thread-3 SYSTEM txid=46ad205edb43 DEBUG: #243316 [REST API] RESTAPIProcessor : REST Request Processing time total_time_to_now_micro_secs=53802021-03-24 02:34:56 (464) API_INT-thread-3 SYSTEM txid=46ad205edb43 DEBUG: Session inactivity timeout changed for unauthorized session. Inactive_interval=300 seconds2021-03-24 02:34:56 (465) API_INT-thread-3 SYSTEM txid=46ad205edb43 *** End #243316 /api/now/table/alm_hardware, user: guest, total time: 0:00:00.000, processing time: 0:00:00.000, SQL time: 0:00:00.001 (count: 3), source: 194.170.64.14 , type:rest, method:null, api_name:null, resource:null, version:null, user_id:5136503cc611227c0183e96598c4f706, response_status:401 If you see this behaviour, please verify if the API call is passed through proxy servers, and the authentication is requested at the proxy level. if the authentication has been requested at the proxy level, the proxy server strips the authorization headers as well, which is needed for Servicenow to process the request. This is not an issue with Servicenow, and customers has to validate the logs from proxy server to identify the reason for this behaviour,