[ovirt-users] How to modify DC's default route setting?

We have to change default route on a production Ovirt system ( ovirt4.3 : engine + 9 hosts + glusterFS subsystem, approx 90 virtual machines.) , due to network enhancement We changed engine's default gateway and could permanently change host's default route by modifying the persistent setting. However, DC's logical network's default route remains unchanged. Consequently, the logical network became out of sync. We would be glad if anyone could instruct us how to change logical network's default route of DC. Thanks in advance, Hideo Goto