Technical Tip: The GUI access on the SD-WAN or ECMP interface is lost after upgrading to v7.4.1, v7.4.2 or v7.4.3

[mkhabbazi]

Description	This article describes that the GUI access on the SD-WAN or ECMP interface is lost after upgrade. After upgrading the FortiGate to v7.4.1, v7.4.2 or v7.4.3, the GUI may not be accessible via the interface that is a member of SD-WAN due to a known issue.  The issue can be confirmed by running a packet capture on GUI traffic. Response from FortiGate is routed out of an incorrect interface creating asymmetric flow: diagnose  sniffer packet  any "host a.b.c.d" 4 0 l     interfaces=[any]  filters=[host a.b.c.d]  wan1 in a.b.c.d  -> x.y.z.v: syn   wan2 out x.y.z.v -> a.b.c.d: syn  ack   a.b.c.d is the IP of the source from outside and x.y.z.v is the wan1 IP.
Scope	FortiGate v7.4.1, v7.4.2 and v7.4.3.
Solution	The issue has been reported with a known issue ID 961796 and it is planned to be resolved in v7.4.4. Workaround: The user can access the GUI via another internal interface that is not part of an SD-WAN link.  Related documents: Known issues  Resolved issues