I am trying to build a network with 3 sub-nets that are connected with cloud as shown in the first figure below by using OPNET 17.5.
after I finish building everything, I try to check links connectivity
one of the sub-nets have 3 links failure, as shown in figure 2

I was trying to delete older links and connect servers again, but the problem is still there!!! And I am trying to work in OPNET 14.5, and I have the same problem. How can I solve it, please!!

I found a solution, and its work!! First, this problem happens because the switch ports do not have enough to cover all connections. To solve this problem, there are 2 solutions: 1. First, delete some PC's then re-connect to servers 2. Or, just use anther switch that has "Adv" in its name because it has more ports.