Thanks MrBilky
Your solution fixed my problem, one of the 10GBe nics on my Hypervisor had taken the IP address for some reason, so I move them to another subnet and reconfigured the vlans on router, rebooted all the servers and switches and now everything seems to have come back to normal. Don't know why it didn't it in the first place, hopefully now it won't happen again.
Thanks for your help.