网络工程 - 回传ip问题 - 吾爱随笔录

所以我有一个奇怪的问题。如果我在以太网接口上配置一个 /30 ip，例如 Router1 上的 10.10.10.1/30 和 Router2 上以太网接口上的 10.10.10.2/30，我可以互相 ping 通... OSPF 没有问题（邻接是形成等）

但是，如果我删除这些配置并将每个 ip 分配给每个路由器上的 loopback0 接口，我将无法 ping 它们并且没有形成邻接。

我已经配置了 OSPF 并且接口被添加到区域 0。我不确定为什么会发生这种情况。如果您需要我的任何配置/输出，请告诉我。

Router 1 - with private ip configured on ethernet interface as ptp link comes up fine.
---------
#sho ip ospf neighbor

Port          Address         Pri State      Neigh Address   Neigh ID        Ev
8/21-8/22     10.10.10.1      1   FULL/OTHER 10.10.10.2      10.10.10.2    5

ethernet 8/21-8/22,OSPF enabled
     IP Address 10.10.10.1, Area 0
     OSPF state ptr2ptr, Pri 1, Cost 1, Options 2, Type pt-2-pt Events 3

Router 2
---------
#sh ip ospf neighbor

Port        Address         Pri State      Neigh Address   Neigh ID        Ev
5/1-5/2     10.10.10.2      1   FULL/OTHER 10.10.10.1      10.10.10.1    14

If I switch to the loopbacks with the publicly routable ip, here is the output:

Router 1
--------
No ospf neighbor formation

lb2,OSPF enabled
     IP Address 111.111.111.1, Area 0
     OSPF state DR, Pri 1, Cost 0, Options 2, Type broadcast Events 5
     Timers(sec): Transit 1, Retrans 5, Hello 10, Dead 40
     DR:  Router ID 111.111.111.1      Interface Address 111.111.111.1
     BDR: Router ID 0.0.0.0           Interface Address 0.0.0.0
     Neighbor Count = 0, Adjacent Neighbor Count= 0

#sh ip route 111.111.111.0
Total number of IP routes: 262007, avail: 137 (out of max 262144)
        Destination     NetMask         Gateway         Port       Cost   Type
        111.111.111.0    255.255.255.252 0.0.0.0         lb2        1      D

Router 2
--------
No ospf neighbor formation

lb1,OSPF enabled
     IP Address 111.111.111.2, Area 0
     OSPF state DR, Pri 1, Cost 0, Options 2, Type broadcast Events 11
     Timers(sec): Transit 1, Retrans 5, Hello 10, Dead 40
     DR:  Router ID 111.111.111.2      Interface Address 111.111.111.2
     BDR: Router ID 0.0.0.0           Interface Address 0.0.0.0
     Neighbor Count = 0, Adjacent Neighbor Count= 0

#sh ip route 111.111.111.0
Total number of IP routes: 262119, avail: 21 (out of max 262144)
        Destination     NetMask         Gateway         Port       Cost   Type
        111.111.111.0    255.255.255.252 0.0.0.0         lb1        1      D