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Cannot connect to a virtual machine that has migrated from ESXi 5.1 to ESXi 5.0 (2043453)
After a virtual machine is migrated from ESXi 5.1 host to ESXi 5.0 hosts, you might not be able to establish a connection with the virtual machine if the uplink port name of the ESXi 5.1 host has more than 31 characters.
The maximum uplink name length supported for ESXi 5.0 is 31 and for ESX5.1 the maximum uplink name length supported is 81. If the uplink port name on the ESXi 5.1 host has more than 31 characters and you migrate a virtual machine from ESXi 5.1 to ESXi 5.0, connection to the vSphere Distributed Switch port is lost and you cannot connect to the migrated virtual machine.
This is a known issue.
Limit the uplink port name length to 31 character in ESXi 5.1 hosts to avoid the issue.
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