Troubleshooting Tip: WhatsApp Desktop cannot connect using FortiProxy or is unable to display QR code

[duenlim]

Description	This article describes an issue where the WhatsApp Desktop app does not work with FortiProxy and provides a solution.
Scope	FortiProxy.
Solution	The WhatsApp Web (https://web.whatsapp.com/) is working fine with the Web browser through FortiProxy. The WhatsApp Desktop can be installed in Windows 8.1 or newer refer to the WhatsApp FAQ. A packet trace is taken when WhatsApp Desktop tries connecting or displaying a QR code. The packet analysis results show client IP has sent and received DNS query/response with the DNS server directly. The DNS response shows the following IP addresses: e12.whatsapp.net 15.197.206.217 15.197.210.208 3.33.221.48 3.33.252.61 a.whatapp.net 157.240.15.61 The client IP then initiates direct connections to the destination's IP without going through the FortiProxy which is highlighted in purple and green colors. This is normally due to an application itself being a proxy-aware issue. Make sure the application is proxy-aware software similar to browsers that continue to use the proxy settings as configured. Workaround: As the application does not reach the WhatsApp services from itself (the proxy configuration) or the Windows Operational System proxy configuration, it is necessary to create an exception traffic on the Firewall to permit the application to show the QR code on the client application.  Assumed the traffic flows are Clients -> Explicit Proxy -> Firewall -> Internet OR In-line Transparent Proxy.  To do this, create a source NAT policy and a transparent policy. Below is an example of configuration: Source NAT policy screen: Instead of 'all' in Source Address, use a subnet to restrict access. The following destinations were captured from the packet capture (sniffer): Source NAT policy from the CLI: config firewall central-snat-map edit 1 set srcintf "port3" set dstintf "port2" set src-addr "all" set dst-addr "chat.cdn.whatsapp.net" "crashlogs.whatsapp.net" "dit.whatsapp.net" "e1.whatsapp.net" "g.whatsapp.net" "graph.whatsapp.com" "web.whatsapp.com" next end Transparent policy: The source is the same as in the previous policy Under the Destination, enter the Internet Service called Meta-Whatsapp, which is a database with the Whatsapp Server address. Leave all the rest as default. Transparent Policy from the CLI: config firewall policy edit 4 set name "internet-open" set srcintf "port3" set dstintf "port2" set srcaddr "all" set action accept set schedule "always" set internet-service enable set internet-service-name "Meta-Whatsapp" set logtraffic all next end Note: This workaround should work with the IP address or FQDN of other application servers too.