简答题 In BGP， we can use Route Reflector and full mesh. Why should we use these？

问答题Neitherexternalroutesnorinterarearouteswillinjectintothisarea.Whatistheareatypeandhowcanyouconfigureit？

问答题一个不多于50台主机的网络，合适它的掩码是多少？

问答题whatisadministrativedistance.

问答题InmulticastnetworkhowtoselectDR？andwhatistheorder？

问答题WhatfieldinIPpacketispreventthepacketfromaroutetorouterforever？