Underscore character is not supported for host names
Starting with 7.4.3, underscore (_) is not allowed in a host name. You can however upgrade to 7.4.3 from an earlier version where the host name included an underscore.
Veritas Access Appliance Release Notes · PDF
Starting with 7.4.3, underscore (_) is not allowed in a host name. You can however upgrade to 7.4.3 from an earlier version where the host name included an underscore.