Beaglbone doesn't connect with pc with sd in it (Ubuntu)

When I try to connect beaglbone black with laptop it connects ..but when I try to connect it with sd card having Ubuntu 12.04 lti precise version doesn't connect ...any fix ??

Did you configure 12.04 to do that? The default image has a script
that does that.

Here is one example of many ways to achive that..