Hello Sprout,
The OSPF network command is used to filter out the IP address of the interfaces that meet the conditions and specify the interfaces to run OSPF.
Conditions: Mask length of the IP addresses are not less than that in the network command. And IP addresses of the interfaces are in the range of the network segment specified by the network command
For example, you can run the network 0.0.0.0 255.255.255.255 command to specify all interfaces that have IP addresses to run OSPF.
The BGP network command is used to import routes from the local IP routing table to BGP. Only the routes in the local IP routing table that exactly match the specified destination address and mask length can be added to the BGP routing table.