[问答题] when you use LSA type 4 in OSPF environment？

what is the difference between the HSRP and VRRP？ 蚕、蛹、蛾又有哪些价值能为人们所利用？ hy you use Spanning-tree？ Difference between PVST & MST. 叉车有自行的底盘，装有可升降的（）和各种可换的取物装置。 ["车架","货叉","门架","悬架"] How many bits represented in DSCP？ when you use LSA type 4 in OSPF environment？