MSR36建立ospf状态机ExStart

MSR3640和S5560替换思科设备，发现OSPF邻居卡在ExStart状态。

查看两端设备OSPF PEER状态全部停留在ExStart

[H3C36-40]display  ospf peer

         OSPF Process 1 with Router ID 10.21.239.129
               Neighbor Brief Information

         OSPF Process 100 with Router ID 10.72.239.246
               Neighbor Brief Information

 Area: 0.0.0.0       
 Router ID       Address         Pri Dead-Time  State             Interface
 10.72.239.241   10.72.239.241   1   40         ExStart/ -        GE0/1

[RT-B]display  ospf peer

                  OSPF Process 1 with Router ID 10.72.239.241
                        Neighbor Brief Information

                  OSPF Process 100 with Router ID 10.72.239.241
                        Neighbor Brief Information

 Area: 0.0.0.0       
 Router ID       Address         Pri Dead-Time  State             Interface
 10.72.239.246   10.72.239.246   1   31         ExStart/ -        GE1/0/21

一、查看两侧配置

MSR3640:

#
interface GigabitEthernet0/1
 port link-mode route
 combo enable copper
 duplex full
 speed 100
 ip binding vpn-instance vpn-rt
 ip address 10.72.239.246 255.255.255.248
 ospf network-type p2p
#

#
ospf 100 router-id 10.72.239.246 vpn-instance vpn-rt
 import-route bgp 65300
 area 0.0.0.0
  network 10.72.239.246 0.0.0.0
#

S5560:

#
interface GigabitEthernet1/0/21
 port link-mode route
 duplex full
 speed 100
 ip address 10.72.239.241 255.255.255.248
 ospf network-type p2p
#

#
ospf 100 router-id 10.72.239.241
 area 0.0.0.0
  network 10.72.239.0 0.0.0.15
  network 10.72.239.24 0.0.0.7
  network 10.72.239.232 0.0.0.7
  network 10.72.239.240 0.0.0.7
#

配置无误。

二、两侧收集debugging分析

S5560:

*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: OSPF 100: Sending packets.                                                     
*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: Source address: 10.72.239.241                                                  
*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: Destination address: 224.0.0.5                                                 
*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: Version 2, Type: 2, Length: 32.                                                
*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: Router: 10.72.239.241, Area: 0.0.0.0, Checksum: 3286.                          
*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: Authentication type: 00, Key(ASCII): 0 0 0 0 0 0 0 0.                          
*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: MTU: 0, Option: _O_E_, R_I_M_MS Bit: _I_M_MS_.                                 
*Nov  19 14:33:21:904 2023 HXIYA OSPF/7/DEBUG: DD Sequence number: b4c6.                                                      
*Nov  19 14:33:26:904 2023 HXIYA OSPF/7/DEBUG: OSPF 100: Sending packets.                                                     
*Nov  19 14:33:26:904 2023 HXIYA OSPF/7/DEBUG: Source address: 10.72.239.241                                                  
*Nov  19 14:33:26:904 2023 HXIYA OSPF/7/DEBUG: Destination address: 224.0.0.5                                                 
*Nov  19 14:33:26:904 2023 HXIYA OSPF/7/DEBUG: Version 2, Type: 2, Length: 32.                                                
*Nov  19 14:33:26:904 2023 HXIYA OSPF/7/DEBUG: Router: 10.72.239.241, Area: 0.0.0.0, Checksum: 3286.                          
*Nov  19 14:33:26:905 2023 HXIYA OSPF/7/DEBUG: Authentication type: 00, Key(ASCII): 0 0 0 0 0 0 0 0.                          
*Nov  19 14:33:26:905 2023 HXIYA OSPF/7/DEBUG: MTU: 0, Option: _O_E_, R_I_M_MS Bit: _I_M_MS_.                                 
*Nov  19 14:33:26:905 2023 HXIYA OSPF/7/DEBUG: DD Sequence number: b4c6. 

S5560发送了DD报文。                            

MSR3640:

*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: OSPF 100: Receiving packets.                                                   
*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: Source address: 10.72.239.241                                                  
*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: Destination address: 224.0.0.5                                                 
*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: Version 2, Type: 2, Length: 32.                                                
*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: Router: 10.72.239.241, Area: 0.0.0.0, Checksum: 3286.                          
*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: Authentication type: 00, Key(ASCII): 0 0 0 0 0 0 0 0.                          
*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: MTU: 0, Option: _O_E_, R_I_M_MS Bit: _I_M_MS_.                                 
*Nov 19 14:26:38:321 2023MSR 36-40 OSPF/7/DEBUG: DD Sequence number: b4c6.                                                      
*Nov 19 14:26:40:316 2023MSR 36-40 OSPF/7/DEBUG: OSPF 100: Sending packets.                                                     
*Nov 19 14:26:40:316 2023MSR 36-40 OSPF/7/DEBUG: Source address: 10.72.239.246                                                  
*Nov 19 14:26:40:317 2023MSR 36-40 OSPF/7/DEBUG: Destination address: 10.72.239.241                                             
*Nov 19 14:26:40:317 2023MSR 36-40 OSPF/7/DEBUG: Version 2, Type: 2, Length: 32.                                                
*Nov 19 14:26:40:317 2023MSR 36-40 OSPF/7/DEBUG: Router: 10.72.239.246, Area: 0.0.0.0, Checksum: 52407.                         
*Nov 19 14:26:40:317 2023MSR 36-40 OSPF/7/DEBUG: Authentication type: 00, Key(ASCII): 0 0 0 0 0 0 0 0.                          
*Nov 19 14:26:40:317 2023MSR 36-40 OSPF/7/DEBUG: MTU: 0, Option: _O_E_, R_I_M_MS Bit: _I_M_MS_.                                 
*Nov 19 14:26:40:317 2023MSR 36-40 OSPF/7/DEBUG: DD Sequence number: f4df.                                                      

MSR3640收到并回复了DD报文，但是S5560上未收到。

根据OSPF邻居的建立过程邻居状态从ExStart到Exchange需要交互一次DD报文。由于MSR3640回复的DD报文S5560未收到，导致OSPF邻居卡在ExStart状态，测试MSR36与S5560直连，OSPF邻居正常full，经排查现场MSR3640和S5560之间还串接了一台二层加密设备，该设备将MSR3640回复的DD报文给过滤了。

协调中间二层加密设备进行配置修改，防止OSPF的DD报文被阻断