WAN Failover - Connection or Interface?
I just installed a secondary Internet connection for a customer, and I set up WAN failover. Not hard to do, and I get the primary/secondary settings. No problem. But I want to clarify something:
When it says that it’s going to probe the connections is it probing the interface, or is it probing something outside that interface? The difference is this: Say the customer is using Comcast as their primary Internet connection. Now Comcast doesn’t just provide you with an Ethernet connection. They provide you with a modem, which interfaces between their cable network and your Ethernet. So if their modem goes down, that’s easy – it’s a failed connection to the primary WAN interface on the SonicWall, and that should fail over.
But what if it’s just the Comcast service that goes down? From an interface perspective, the connection is still up. There’s just no way to reach anything. But it’s not a “down” connection. So if it’s probing just the interface, it won’t fail over to the secondary WAN. OTOH, if it’s actually checking a connection to something outside, then it doesn’t matter.
So the questions are:
- Is it probing the interface or the Internet?
- If it’s just probing the interface, is there any way to make it try to hit something on the Internet, so as to make sure the failover will work properly?