Fortigate 201E Losses Connection to DNS whenever both connections on SD WAN are active

[jkingston]

Hi guys, so yesterday my colleagues noticed that our DNS servers were unable to resolve FQDNs, Fortiguard was not able to resolve them as well. When we checked the two ISP links that make up our SD-WAN we noticed that whenever one was removed the issue would be resolved. However, having them both in causes DNS issues.

The first ISP/WAN link is a static IP; the second ISP/WAN is DHCP.

I have unticked the override DNS on the second WAN and even changed the DNS under the Network>>DNS.

Nothing thus far has worked.

I would really appreciate some help with this, I have never observed this on any networks I have worked on before

[Jirka1]

Hi,

check this: https://docs.fortinet.com...lf-originating-traffic