I have a question concerning default gateways in RHEL. In Linux, the default gateway does not have to be associated with a specific interface - when you look at your routing table with route -n, your default gateway can be associated with the default route on the last line, and doesn't have to be specifically tied to eth0 - eth0 can just have a default route that points to a default gateway. (In Windows a specific default gateway is normally configured with every NIC, rather than having a NIC be associated with a default route, which is in turn assoicated with default gateway).
So if I open up in my network configuration GUI in linux for a specific NIC and see that there is nothing in the default gateway field, it doesn't necessarily mean I have no network connectivity (as it would in Windows). I could still have a default gateway configured for my default route, and eth0 just uses the default route even though the GUI shows nothing in the "default gateway" field for eth0's properties.
My question is, my provisioning process leaves the "default gateway" field as seen in the GUI for each NIC blank but gives network connectivity anyway through the default route. Is there any reason for populating the default gateway specifically for eth0 rather than just using the default route? Are there any gotchas to that network configuration that I should know about? What is the standard / best practice concerning this? Thanks