You have a local working copy of a svn repository and the server repository changed the ip for example. So you can try something like inside your working copy:
svn switch --relocate http://10.0.0.1/svn/repository/projects/foo http://10.0.0.2/svn/repository/projects/foo
Where 10.0.0.1 is the old address of the repository and the 10.0.0.2 is the new one. The path for the copy remained the same /svn/repository/projects/foo.