The Task Status page only tells you where the client is getting it's tasks.

Packages come via a completely different methodology, and in several circumstances, you may have more than 1 package source for the same package (depends on site definitions).  So no, that's not where you'll see where packages come from.

You can see where packages come from only from the package itself.  Double-click on the package in the Agent, then go to the download tab, and voila - where the packages are coming from.

As for changing it, yes, it's easy.  That is what Site Definitions are all about!  :-)

You build sites based on subnets.  So you go to Settings | Notification Server | Site Server Settings, highlight Sites at the left, and create one.  From here, you assign subnets to the sites, and clients in those subnets are now defined to those sites.  Then you assign Sites to Site Servers.

The tricky part is the Package Servers.  There are constrained and unconstrained package servers.  By default, all are unconstrained.  That allows you to assign as many package servers to the same site as you want (via assigning a site to the package server, actually).

If you really want to be tricky then, you can unconstrain only 1 package server in a site, and constrain the others in that site, and they will have to get their packages from the unconstrained server, who gets it's packages from the NS, but the clients can pick from any of them in the site.

If you want to FORCE a client to 1 package server, make sure only 1 package server is assigned to the site the client is assigned to, and voila.

Well mostly.  Remember, you can't take a site server out of it's own subnet.  And then voila.  If you forget that, it can be interesting, because the NS will add it back over, and over, and over.....  :D :D

Have fun!!