How To Persist The Default Gateway Configuration in Case of Multiple Interfaces?

Problem

How to persist the default gateway configuration in case of multiple interfaces attached to a system?

Environment

• Platform9 Managed OpenStack - All Versions
• CentOS 7.x

Procedure

1. By default the system will prefer the gateway of the latest interface that was brought online. If the gateway is defined for all the interfaces in the interface config file, add the option of DEFROUTE=yes for the interface whose gateway should be used for preferred network communication.

$ less /etc/sysconfig/network-scripts/ifcfg-eth1

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DEFROUTE=yes

Additional Information

Alternative way is to set DEFROUTE=no in all other interface configuration except for the interface which we want to use by default for all communication.