The message indicates that the device does not understand the packet received by it. The reason for that could range from a simple configuration problem (recheck your configured passwords, access-list etc) or might have to do with incompatible software versions. Other messages accompanying this one will give you a better idea of what went wrong.
Learn, share, save
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.