If you use different network and IP schemes in production and DR sites, in the common case you would need to change the network configuration of a VM replica before you fail over to it. To eliminate the need for manual replica reconfiguration and ensure minimum failover downtime, Veeam Backup & Replication offers possibilities of network mapping and automatic IP address transformation.
By default, a replicated VM uses the same network configuration as the original VM. If the network in the DR site does not match the production network, you can create a network mapping table for the replication job. The table maps source networks to target networks.
During every job run, Veeam Backup & Replication checks the network configuration of the original VM against the mapping table. If the original VM network matches a source network in the table, Veeam Backup & Replication updates the replica configuration file to replace the source network with the target one. Thus, network settings of a VM replica are always kept up to date with the DR site requirements. In case you choose to fail over to the VM replica, it will be connected to the correct network.
For Microsoft Windows VMs, Veeam Backup & Replication automates reconfiguration of VM IP addresses. If the IP addressing scheme in the production site differs from the DR site scheme, you can create a number of re‑IP rules for the replication job.
When you fail over to the replica, Veeam Backup & Replication checks if any of the specified re-IP rules apply to the replica. If a rule applies, Veeam Backup & Replication mounts VM disks of the replica to the backup server and changes its IP address configuration using the Microsoft Windows registry. If failover is undone for any reason or if you fail back to the original location, replica IP address is changed back to the pre-failover state.
If you plan to configure re-IP rules, mind the following limitations:
- Veeam Backup & Replication allows you to configure re-IP rules for Microsoft Windows VMs only. If you want to configure re-IP rules for Linux VMs, use in-guest scripts as suggested on Veeam community forums at https://forums.veeam.com/.
- Replica re-IP works only if you perform replica failover using Veeam Backup & Replication. If you power on a VM replica in some other way, for example, manually using vSphere Client, re-IP rules will not be applied to it.