单项选择题
An attacker sends a low rate of TCP SYN segments to hosts， hoping that at least one port replies. Which type of an attack does this scenario describe？（）
A.DoS B.SYN flood C.port scanning D.IP address sweep
多项选择题 Whatarethreemainphasesofanattack？（）
多项选择题 WhichtwostatementsabouttheuseofSCREENoptionsarecorrect？（）
多项选择题 WhichtwoexternalauthenticationservertypesaresupportedbyJUNOSSoftwareforfirewalluser authentication？（）
