TO define via in allegro

[jai_vardhan]

Hi plz any body tell me how to define via in allegro as i am facing problem when changing layer from top to bottom it is saying no via defined.

 

[hobbss]

First, use the padstack editor to create your own via padstack. Then open the constraint manager. Select the Physical Constraints "tab" (on left). Expand "Net" and select "All Layers." In the 8th column (titled "Vias"), click in one of the blank cells. Select your newly created via padstack, and double click it to add it to the via list. Copy this to all traces that you want to have the same via. If desired, you can place multiple via padstacks in the list in decreasing priority. You can then select which via to use when routing the board.