I have two domains xyz.com & abc.com both refere to the same IP address One as a physical host and other as a virtual host.

What i am afraid is that whether this has some sort of negative impact on search engine rankings... and interestingly my virtual host is having a better ranking than my physical host. Some one told that mirroring or redirection is considered as spam by SE's specially Goolgle.

Can anyone suggest me osme SE friendly way of doing this as i want to keep both domains as both are popular and well promoted.

Thank you in advance for any suggestions.