You (really) asked 2 related questions:
- Can I redirect
somename.domain.com
to anothername.somedomain.com
?
- Can SVN-clients use old name, but intecat with new host?
And short answers will be
Longer versions
For redirecting old hostname to new you have and can use at least two variations (with the same final result)
- At the DNS level and CNAME record, which will alias new name to new:
somename.domain.com. IN CNAME anothername.somedomain.com
on request of somename will answer with data from anothername
- In the Apache's config for host of location somename you can add redirect to anothername Apache's
But: it will work only on browsers's level - when you'll try to use this redirected location as target for any Subversion's command, you'll get error "Repository moved, please relocate" and you must relocate all old resources to new URL.
Good news for your
All externals definition are written as svn-properties inside source repo, you can get list of these externals (with values) and update with the new values, and this operation (theoretically) can be automated
svn propget -R svn:externals . > FILE
in the root of working copy for getting externals
svn propset svn:externals --target FILE
for defining new externals in batch