The OCID of the network attached to the DRG.
This is the OCID of the route table that is used to route the traffic as it enters a VCN through this attachment.
For information about why you would associate a route table with a DRG attachment, see [Advanced Scenario: Transit Routing](https://docs.cloud.oracle.com/iaas/Content/Network/Tasks/transitrouting.htm). For information about why you would associate a route table with a DRG attachment, see:
[Transit Routing: Access to Multiple VCNs in Same Region](https://docs.cloud.oracle.com/iaas/Content/Network/Tasks/transitrouting.htm) * [Transit Routing: Private Access to Oracle Services](https://docs.cloud.oracle.com/iaas/Content/Network/Tasks/transitroutingoracleservices.htm)
Indicates whether the VCN CIDRs or the individual subnet CIDRs are imported from the attachment. Routes from the VCN ingress route table are always imported.
Specifies the VCN Attachment