Some companies have built out their disaster recovery site with a stretched layer 2 network or even a disjoint layer 2 network that shares the same IP addresses with their production sites. This is great because VMs don’t need to change IP Addresses if there is a failover event. This post goes over what options we have if you need to change IP Addresses during your failover.
SRM 5.8 has a wonderful new way to manage IP Addresses between datacenters. Prior to SRM 5.8 each VM needed to be manually updated with a new IP Address or done in bulk with a CSV template (show later in this post) if you had to re-IP your VMs. Now with SRM 5.8 we can do a network mapping to make our lives much easier. This is one of the best new features of SRM 5.8 in my opinion.
Go to your sites in “Site Recovery” and click the Manage tab. Here, you’ll see our network mappings again. Click the networks that you’ve mapped previously and then you can click the “Add…” button to create some IP Customization Rules.
When the “Add IP Customization Rule” screen comes up, you can see that we can now map the networks to one another and the virtual machine will keep the host bits the same between networks. For example, if you have a VM on the 10.10.50.0/24 network with an IP Address of 10.10.50.100, and it needs to failover to the 10.10.70.0/24 network, it will keep it’s hosts bits the same, and just change the network, making it 10.10.70.100 at the DR site. SIMPLE!!!!
Obviously, there are a few other things that you’ll need to modify such as DNS Servers, suffixes and of course the default gateway.
Once you’ve created your IP Customization Rules, you can see them listed below the network mappings for your virtual machines.
Manual IP Customization
If the subnet mapping spelled out above doesn’t work, you can manually customize an IP Address of each VM. Go into your recovery plans and find the virtual machine to customize. Right click and choose “Configure Recovery…”
Click the IP Customization Tab. Here you’ll see that you can add IP Addresses for both sites. Be sure to enter IP information in for both sites. If you failover to the recovery site and didn’t set the protected site IP Addresses, you’ll have some IP issues when you try to fail back.
Click either the “Configure Protection…” or “Configure Recovery…” and then you can enter your IP information. Again, be sure to do both sites.
BULK IP Customizer
Many times it’s not practical to modify the IP addresses of every individual VM as they are configured. Luckily VMware has provided a way to bulk upload IP addresses.
From an SRM server, open a command prompt and change the working directory to: c:Program FilesVMwareVMware vCenter Site Recovery Managerbin
NOTE: Path may be different depending on your install location.
Generate a .CSV file to edit your IP Addresses by running dr-ip-customizer.exe with the –cfg, –cmd –vc -i –out switches.
–cfg should be the location of the vmware-dr.xml file. –cmd should be “Generate”, –vc lists the vCenter server, and –out lists the location to generate the .csv file.
Example: dr-ip-customizer.exe –cfg “C:Program filesVMwareVMware vCenter Site Recovery ManagerConfigvmware-dr.xml” –cmd generate –vc FQDNofvCenter -i –out c:ipaddys.csv
Open the .csv file and fill out the information. Notice that there are two entries for the VM. This is because there are two vCenters and in order to do protection and fail back we need the IP Addresses for both sides.
Once the IP Address information is entered, run the customizer again with the –cmd “Apply” and –CSV file location.
Example: dr-ip-customizer.exe –cfg “C:Program filesVMwareVMware vCenter Site Recovery ManagerConfigvmware-dr.xml” –cmd apply –vc FQDNofvCenter -i –csv c:ipaddys.csv