Refer to the RFC document:
0.0.0.0/8-Addresses in this block refer to source hosts on "this"
Network. Address 0.0.0.0/32 may be used as a source address for this
Host on this network; other addresses within 0.0.0.0/8 may be used
Refer to specified hosts on this network ([RFC1122], Section 3.2.1.3 ).
According to the RFC, it not only represents the local machine, 0.0.0.0/8 can represent all hosts in the local network, 0.0.0.0/32 can be used as the source address of the local machine, 0.0.0.0/8 can also represent a specific host on the network. In combination, it can be said that 0.0.0.0 represents the entire network. It helps the router send packets that cannot be queried in the routing table. If no network route is configured, all packages that cannot be queried in the routing table will be sent to the route for all networks.
In the vro configuration, 0.0.0.0/0 indicates the default route. It helps the vro send packages that cannot be queried in the route table. If no network route is configured, all packages that cannot be queried in the routing table will be sent to the route for all networks. Strictly speaking, 0.0.0.0 is no longer a real IP address. It represents a set of unknown hosts and destination networks. "Unknown" indicates that no specific entries in the local route table indicate how to arrive