单项选择题
A. RFC 1769 and mere publications
B. Real standards of RFC 1918
C. RFC 1669 real standards andmere publications
D. Real standards and mere publications RFC 1796
E. None of the above
单项选择题 SinceHTTPisoneofthemostcommonprotocolsusedintheinternet，whatshouldbedoneatafirewallleveltoensurethattheprotocolisbeingused correctly？（）
单项选择题 WhatCiscotechnologyprotectsagainstSpanning-TreeProtocolmanipulation？（）
单项选择题 WhichofthefollowingisanexampleofasecuritytechnologythatcouldbeenabledbyNetflow？（）