No protocol specified
 

How can I solve this problem on Ubuntu Sir?

I suspect you need to specify a protocol.

EDIT: Another approach is an internet search for the error message. You will get a lot of results, which you can narrow down by providing more information about the context in which this message pops up.

If you insist on getting answers from Linuxquestions, just throwing out an error message without any other information won't get you anywhere. You might want to read the link about how to use this site in my signature.

At least tell us what you were doing when you got that message. What did you input to make it say that?