I am in process of migrating my old domain (www.oldurl.com) to new domain (www.newurl.com). Almost all the content,URL structure as well database is same except for few URL's and only difference will be in the domain name.

I have made entries in the Apache's .htaccess file to set 301 redirect and currently have blocked all search engines from crawling my new domain by setting in robot.txt file.

I am not sure how i will handle the duplicate content issue as when i will make the new domain go live.

• Should i block search engines to index/crawl my old domain?

i am new to this field and not sure if this is actually any duplicate content issue or not.