  We consider a regular random network where each node has exactly three
neighbours. Ising spins at the network nodes interact antiferromagnetically
along the links. The clustering coefficient $C$ is tuned from zero to 1/3 by
adding new links. At the same time, the density of geometrically frustrated
links increases. We calculate the magnetic specific heat, the spin
susceptibility and the Edwards-Anderson order parameter $q$ by means of the
heat-bath Monte Carlo simulations. The aim is the transition temperature $T_x$
dependence on the clustering coefficient $C$. The results are compared with the
predictions of the Bethe approximation. At C=0, the network is bipartite and
the low temperature phase is antiferromagnetic. When $C$ increases, the
critical temperature falls down towards the values which are close to the
theoretical predictions for the spin-glass phase.
