![tor router vm esxi 6.5 tor router vm esxi 6.5](https://i0.wp.com/davidbombal.com/wp-content/uploads/2018/02/GNS3-VMware-ESXi2.jpg)
If you cannot get up to ESXi 5.5 on your existing host, you'll need to stop at vCenter 6.0 to support your ESXI 5.1 configuration, and pull everything up to v6.0 from there, you will be able to look at upgrading to vCenter 6.5 or 6.7, which you could then get up to 7.0.
#Tor router vm esxi 6.5 install
From my initial analysis, you'll have to install no higher than vCenter 6.5 to support your old VMs if you can get them up to ESXi 5.5 on existing host for upgrading to newer versions. Your vCenter version will help, but vCenter 7 only supports ESXi 6.5 and up, so you would need to stop at a lower version of vCenter first to support your old VMs and upgrade them to newer versions before you could move up further. Much as they've suggested, I'll echo as well, that you're probably looking at trying to update to the newest version of 5.X you can get on your current hardware, and then move to ESXi 6.X on another piece of hardware that you can then update further to try and get into supported territory.
![tor router vm esxi 6.5 tor router vm esxi 6.5](https://vmanalyst.com/wp-content/uploads/2021/05/image-29.png)
As the others have said, 5.1 is so far out of date, that you're looking at a multi-stepped upgrade to try and get current.