非對稱式路由與多個網路路徑(路由去回不同路)

https://docs.microsoft.com/zh-tw/azure/expressroute/expressroute-asymmetric-routing
Asymmetric routing with multiple network path
越來越多的網路環境不是單一出口，很常遇到因路由去回不同路，造成各式樣的網路不通問題，這篇說明算是蠻清楚的，雖然需要一點耐心且網路基礎，但至少把各細節都介紹。

當然各廠牌設備其實都有解決的方式。

• 舉Fortigate例子

 config system settings

set asymroute enable

end

有vdom狀況下

config vdom

edit

config system settings

set asymroute enable

end

end

If you enable asymmetric routing, antivirus and intrusion prevention systems will not be effective. Your FortiGate unit will be unaware of connections and treat each packet individually. It will become a stateless firewall.

http://help.fortinet.com/fos50hlp/54/Content/FortiOS/fortigate-networking-54/Interfaces/VLANs/Asymmetric%20routing.htm

• Key word : asymmetric routing