Modeling failures 。Link failure A link no longer reliably delivers messages [Node failure]Crash failure A node halts(as if unplugging power supply) [Node failure]Byzantine failure A node can behave arbitrarily ------- timeModeling failures • Link failure • A link no longer reliably delivers messages • [Node failure] Crash failure • A node halts (as if unplugging power supply) • [Node failure] Byzantine failure • A node can behave arbitrarily time