Jack is skiing from the top of the mountain. He doesn't look very confident. You can ask:____________________________________________? (ski from the top of the mountain, before)
【单选题】下面的拓扑中,假设所有的路由都宣告正确,从最上面的路由器路由表为什么到12.0.0.0网段的路由没有显示两条,可能有哪些原因(最上面的路由器是R1) R1#sh ip route eigrp 12.0.0.0/30 is subnetted, 1 subnets D 12.0.0.0 [90/3868416] via 20.0.0.2, 00:51:44, Serial1/2