问答题
255.255.255.192
whatisadministrativedistance.
问答题what is administrative distance.
InmulticastnetworkhowtoselectDR？andwhatistheorder？
问答题In multicast network how to select DR？ and what is the order？
WhatfieldinIPpacketispreventthepacketfromaroutetorouter...
问答题What field in IP packet is prevent the packet from a route to router forever？
