private static void loadTopologyLinkMetric(List<String> tokens, Link<?> link) throws Exception {
		if ((tokens.size() < 2) || (tokens.size() > 3))
			throw new Exception("Invalid number of parameters in link metric declaration");
		HardwareInterface<? extends Message> if1= link.getHead();
		IPInterfaceAdapter ip_if1= ((IPHost) if1.getNode()).getIPLayer().getInterfaceByName(if1.getName());
		HardwareInterface<? extends Message> if2= link.getTail();
		IPInterfaceAdapter ip_if2= ((IPHost) if2.getNode()).getIPLayer().getInterfaceByName(if2.getName());
		String token= tokens.get(1);
		int metric;
		if (token.equals("?"))
			metric= Integer.MAX_VALUE;
		else
			metric= Integer.valueOf(token);
		ip_if1.setMetric(metric);
		
		if (tokens.size() == 3) {
			token= tokens.get(2);
			if (token.equals("?"))
				metric= Integer.MAX_VALUE;
			else
				metric= Integer.valueOf(token);
		}
		ip_if2.setMetric(metric);
	}