vectorization and matlab functions for multiple for loops and conditionals within

I want my code to run faster and this section seems like its making the code run slower.

I tried to vectorize it and use meshgrid but couldn't figure it out.

 %linkswithpackets in node matrix form
            l=1;
            packets=zeros(N,N);
            for m=1:N
                for n=1:N
                    packets(m,n)=linkswithpacket(l);
                    l=l+1;
                end
            end


            %generate all noma node combinations with packets
            combinations_withpackets=[];
            for i=1:N
                for j=1:N
                    if(i~=j)
                       for k=1:N
                           if((k~=i)&&(k~=j))
                               if((packets(i,j)>0)&&(packets(i,k)>0))   
                                   combinations_withpackets=[combinations_withpackets;i j k];
                               end
                           end
                       end
                    end
                end
            end

This is supposed to create an array of the form [i j k] where i and j and k are nodes and at each row of the array they are not equal to each other. It adds an [i j k] combination to combinations_withpackets if there are packets from node i to j and node i to k.