Let me start of by saying that I do not specialize in networking, I am in the process of adding additional VMs to a testing environment and wanted some recommendations.
In this case I am running a single ESXI 5.1 host and a single Vcenter management server.
The problem is, I need another range of IP addresses added to the existing setup; hopefully without reconfiguring everything.
Currently the esxi host is configured to IP: 192.168.100.200, gateway: 192.168.100.1 and subnet: 255.255.255.0. All of the VMs are running some version of linux with hard coded IP addresses in that range, and using that subnet. The VMs I am about to deploy I want to be on the 192.168.101.X network.
Is it possible to add an additional subnet to this existing system that will also communicate with the current subnet?
The esxi host has 6 physical NICs but only one connected as it is only a testing system; not sure if that matters.
Are there any other ways to accomplish this hopefully without restarting or at least reconfiguring the IP addresses for each VM?
Reason: Due to the configuration of the VMs to run the applications that we need I am using a large amount of the current IPs in the potential range (mostly VIPs). I will be setting up a new version of this “environment” while keeping the old one, thus potentially running out of IP addresses.
Best Answer
Tell your network guys to create the network 192.168.101.0.
Then add it as an additional VLAN to your existing uplink and add a port group for this network to your virtual switch.
Or create a new virtual switch for this network and get yourself an uplink (you've got 5 NICs left) for this network.
You wont have any downtime. If your VMs in 192.168.100.0 and 192.168.101.0 have to talk to each other, that's your networking team's job.