单项选择题
What is the purpose of the OSPF hello packet？（）
A. advertises reachable networks B. acknowledges the receipt of update packets C. establishes and maintains neighbor relationships D. describes the contents of the link-state database
多项选择题 WhatarethethreeOSPFauthenticationmethodssupportedontheERXEdgeRouter？（）
单项选择题 WhenconfiguringOSPFontheERX，whatisthedefaultauto-costreference-bandwidthvalue？（）
单项选择题 Whywouldyoumakeanon-backboneareaastubornot-so-stubbyarea？（）
