yum enhancement request - save bandwidth

["Jerry Williams" <jwilliam xmission com>]

Most of the time I already have a mirror of the updates.
And it seems like a waste of bandwidth to download things again.

Would it be possible to add a line to yum to say look here first.
And "here" could be either another directory that might be nfs mounted or a
web site.  If you find the package then use the local copy if not then go
and pull it down from whatever site.

I am only talking about packages, not headers.

Or if I am just doing a yum install and have a CD/DVD with the package on it
and it would be nice to again get it local if possible.  Maybe even list
multiple local places.  Like is it on a CD/DVD in the drive?  Nope is it on
a local web site nope,  then get it off the web.

I do want it to go to the web and find out what the current version is and
if I have it great, it not go get it.

If this is already done, please point me at the docs so that I can use it.
Thanks!

Jerry