Technical Tip: How does 'diagnose sys waninfo ipify' command identify the WAN ip address of the FortiGate

[nithincs]

Description	This article explains the communication flow used by the FortiGate to identify the public IP.
Scope	FortiGate
Solution	To get the public IP address, the FortiGate performs a series of steps: DNS Resolution: The FortiGate must first successfully resolve the hostname api.ipify.org to its corresponding server IP address. This is a crucial initial step to ensure connectivity.. TCP and TLS Handshake: After resolving the hostname, the FortiGate initiates a TCP and TLS handshake with the resolved server IP. HTTP Request: A GET request is then sent to the https://api.ipify.org/ server.: "request": {           "method": "GET",           "url": "https://api.ipify.org/",           "httpVersion": "http/2.0",           "headers": [             {               "name": ":authority",               "value": "api.ipify.org"             },             {               "name": ":method",               "value": "GET"             },             {               "name": ":path",               "value": "/"             },             { . . . .             {               "name": "user-agent",               "value": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36"             }           ],           "queryString": [],           "cookies": [],           "headersSize": -1,           "bodySize": 0         }, Response: In response to the request, the api.ipify.org server sends back the public IP address of the source that connected to it. The response has a status code of 200, indicating success, and the content type is text/plain. The public IP address is returned in the body of the response. "response": {           "status": 200,           "statusText": "",           "httpVersion": "http/2.0",           "headers": [             {               "name": "cf-cache-status",               "value": "DYNAMIC"             },             {               "name": "cf-ray",               "value": "98492fa3fc6f7937-AMD"             },             {               "name": "content-encoding",               "value": "br"             },             {               "name": "content-type",               "value": "text/plain"             },             {               "name": "date",               "value": "Thu, 25 Sep 2025 08:35:05 GMT"             },             {               "name": "server",               "value": "cloudflare"             },             {               "name": "vary",               "value": "Origin"             }           ],           "cookies": [],           "content": {             "size": 13,             "mimeType": "text/plain",             "text": "X.X.X.235" <<<<< Public ip information shared by "api.ipify.org"           },           "redirectURL": "",           "headersSize": -1,           "bodySize": -1,           "_transferSize": 143,           "_error": null,           "_fetchedViaServiceWorker": false         },