4台路由器连在同一个二层交换机上，接口同网段，为什么有2台之间ospf是2way状态

 sysname r10
#
ospf 1
 area 0.0.0.0
  network 2.2.2.0 0.0.0.255
  network 5.5.5.0 0.0.0.255

interface GigabitEthernet0/0
 port link-mode route
 combo enable copper
 ip address 5.5.5.1 255.255.255.0
#
interface GigabitEthernet0/1
 port link-mode route
 combo enable copper
 ip address 2.2.2.5 255.255.255.0

[r10]dis ospf peer

         OSPF Process 1 with Router ID 2.2.2.5
               Neighbor Brief Information

 Area: 0.0.0.0
 Router ID       Address         Pri Dead-Time  State             Interface
 6.1.1.1         5.5.5.2         1   39         Full/DR           GE0/0
 2.2.2.1         2.2.2.1         1   33         2-Way/ -          GE0/1
 3.1.1.1         2.2.2.2         1   37         Full/BDR          GE0/1
 4.1.1.1         2.2.2.3         1   39         Full/DR           GE0/1
[r10]
------------------------------------------------------------------

ospf 1
 area 0.0.0.0
  network 1.1.1.0 0.0.0.255
  network 2.2.2.0 0.0.0.255
#

interface GigabitEthernet0/0
 port link-mode route
 combo enable copper
 ip address 1.1.1.1 255.255.255.0
#
interface GigabitEthernet0/1
 port link-mode route
 combo enable copper
 ip address 2.2.2.1 255.255.255.0
 ipsec apply policy r2
#

<r2>dis ospf peer

         OSPF Process 1 with Router ID 2.2.2.1
               Neighbor Brief Information

 Area: 0.0.0.0
 Router ID       Address         Pri Dead-Time  State             Interface
 1.1.1.2         1.1.1.2         1   33         Full/DR           GE0/0
 1.1.1.3         1.1.1.3         1   34         Full/BDR          GE0/0
 3.1.1.1         2.2.2.2         1   32         Full/BDR          GE0/1
 4.1.1.1         2.2.2.3         1   34         Full/DR           GE0/1
 2.2.2.5         2.2.2.5         1   35         2-Way/ -          GE0/1

-----------------------------------------------------------------------

 sysname r4
#
ospf 1
 area 0.0.0.0
  network 2.2.2.0 0.0.0.255
  network 4.1.1.0 0.0.0.255
#

interface GigabitEthernet0/0
 port link-mode route
 combo enable copper
 ip address 4.1.1.1 255.255.255.0
#
interface GigabitEthernet0/1
 port link-mode route
 combo enable copper
 ip address 2.2.2.3 255.255.255.0

[r4]dis ospf peer

         OSPF Process 1 with Router ID 4.1.1.1
               Neighbor Brief Information

 Area: 0.0.0.0
 Router ID       Address         Pri Dead-Time  State             Interface
 2.2.2.1         2.2.2.1         1   31         Full/DROther      GE0/1
 3.1.1.1         2.2.2.2         1   36         Full/BDR          GE0/1
 2.2.2.5         2.2.2.5         1   39         Full/DROther      GE0/1

所有的g0/1口都连在同一个二层交换机上