(1)接口上没有激活ospf
就是在network语句的时候没有匹配清楚，比如配置了错误的反掩码不对，在show ip ospf interface的时候不会显示你希望激活的接口。使用show ip ospf interface来验证。
这时候的邻居表是空的
>R2#show ip ospf neighborR2#
(2)物理层或者是数据链路层协议down.使用show ip int brief 或者是 show int type nomber会导致ospf packet 封装失败。
(3)建立邻居的接口被passive掉
R2#show ip ospf interface Ethernet 0
Ethernet0 is up, line protocol is upInternet Address 131.108.1.2/24, Area 0Process ID 1, Router ID 131.108.1.2, Network Type BROADCAST, Cost: 10Transmit Delay is 1 sec, State DR, Priority 1Designated Router (ID) 131.108.1.2, Interface address 131.108.1.2No backup designated router on this networkTimer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5No Hellos (Passive interface)Neighbor Count is 0, Adjacent neighbor count is 0Suppress hello for 0 neighbor(s)
(4)OSPF的hello组播地址被ACL Block
R1#interface Ethernet0ip address 131.108.1.1 255.255.255.0ip access-group 100 in!access-list 100 permit tcp any anyaccess-list 100 permit udp any anyaccess-list 101 permit ip 131.108.1.0 0.0.0.255 host 224.0.0.5
R2#interface Ethernet0ip address 131.108.1.2 255.255.255.0ip access-group 100 in!access-list 100 permit tcp any anyaccess-list 100 permit udp any anyaccess-list 101 permit ip 131.108.1.0 0.0.0.255 host 224.0.0.5
R2#debug ip packet 101 detailIP packet debugging is on (detailed) for access list 101IP: s=131.108.1.2 (Ethernet0), d=224.0.0.5, len 68, access denied, proto=89
这时候的邻居关系是INIT
R2#show ip ospf neighborNeighbor ID Pri State Dead Time Address Interface131.108.2.1 1 INIT/- 00:00:33 131.108.1.1 Ethernet0
R1#show access-list 101Extended IP access list 101permit ip 131.108.1.0 0.0.0.3 host 224.0.0.5 (8 matches)R1#debug ip packet 101 detailIP packet debugging is on (detailed) for access list 101R1#IP: s=131.108.1.1 (local), d=224.0.0.5 (Ethernet0), len 60, sending broad/multicast,proto=89IP: s=131.108.1.2 (Ethernet0), d=224.0.0.5, len 82, access denied, proto=89IP: s=131.108.1.1 (local), d=224.0.0.5 (Ethernet0), len 60, sending broad/multicast,proto=89
IP: s=131.108.1.2 (Ethernet0), d=224.0.0.5, len 82,access denied, proto=89
(5)在broadcast链路上的子网掩码不匹配
(6)Hello/dead 间隔不匹配
(7)认证方式或者是认证密码不匹配
使用debug ip ospf adj 来查看,可以自己使用不同的情况来验证
(8)两台路由器处于不同的AREA
R1#debug ip ospf adjOSPF adjacency events debugging is onR1#OSPF: Rcv pkt from 131.108.1.2, Ethernet0, area 0.0.0.0mismatch area 0.0.0.1 in the header
R2#show log%OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 131.108.1.1, Ethernet0
(9)Stub/transit/NSSA 区域类型不匹配
这个是常常不小心会被忘记的。
R1#debug ip ospf adjOSPF adjacency events debugging is onR1#OSPF: Rcv hello from 131.108.0.1 area 1 from Ethernet0 131.108.1.2OSPF: Hello from 131.108.1.2 with mismatched Stub/Transit area option bit
R1#debug ip ospf adjOSPF adjacency events debugging is onR1#OSPF: Rcv hello from 131.108.0.1 area 1 from Ethernet0 131.108.1.2OSPF: Hello from 131.108.1.2 with mismatched NSSA option bit
(1)接口上没有激活ospf
就是在network语句的时候没有匹配清楚，比如配置了错误的反掩码不对，在show ip ospf interface的时候不会显示你希望激活的接口。使用show ip ospf interface来验证。
这时候的邻居表是空的
>R2#show ip ospf neighborR2#
(2)物理层或者是数据链路层协议down.使用show ip int brief 或者是 show int type nomber会导致ospf packet 封装失败。
(3)建立邻居的接口被passive掉
R2#show ip ospf interface Ethernet 0
Ethernet0 is up, line protocol is upInternet Address 131.108.1.2/24, Area 0Process ID 1, Router ID 131.108.1.2, Network Type BROADCAST, Cost: 10Transmit Delay is 1 sec, State DR, Priority 1Designated Router (ID) 131.108.1.2, Interface address 131.108.1.2No backup designated router on this networkTimer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 No Hellos (Passive interface)Neighbor Count is 0, Adjacent neighbor count is 0Suppress hello for 0 neighbor(s)
(4)OSPF的hello组播地址被ACL Block
R1#interface Ethernet0ip address 131.108.1.1 255.255.255.0ip access-group 100 in!access-list 100 permit tcp any anyaccess-list 100 permit udp any anyaccess-list 101 permit ip 131.108.1.0 0.0.0.255 host 224.0.0.5
R2#interface Ethernet0ip address 131.108.1.2 255.255.255.0ip access-group 100 in!access-list 100 permit tcp any anyaccess-list 100 permit udp any anyaccess-list 101 permit ip 131.108.1.0 0.0.0.255 host 224.0.0.5
R2#debug ip packet 101 detailIP packet debugging is on (detailed) for access list 101IP: s=131.108.1.2 (Ethernet0), d=224.0.0.5, len 68, access denied, proto=89
这时候的邻居关系是INIT
R2#show ip ospf neighborNeighbor ID Pri State Dead Time Address Interface131.108.2.1 1 INIT/- 00:00:33 131.108.1.1 Ethernet0
R1#show access-list 101Extended IP access list 101permit ip 131.108.1.0 0.0.0.3 host 224.0.0.5 (8 matches)R1#debug ip packet 101 detailIP packet debugging is on (detailed) for access list 101R1#IP: s=131.108.1.1 (local), d=224.0.0.5 (Ethernet0), len 60, sending broad/multicast,proto=89IP: s=131.108.1.2 (Ethernet0), d=224.0.0.5, len 82, access denied, proto=89IP: s=131.108.1.1 (local), d=224.0.0.5 (Ethernet0), len 60, sending broad/multicast,proto=89
IP: s=131.108.1.2 (Ethernet0), d=224.0.0.5, len 82,access denied, proto=89
(5)在broadcast链路上的子网掩码不匹配
(6)Hello/dead 间隔不匹配
(7)认证方式或者是认证密码不匹配
使用debug ip ospf adj 来查看,可以自己使用不同的情况来验证
(8)两台路由器处于不同的AREA
R1#debug ip ospf adjOSPF adjacency events debugging is onR1#OSPF: Rcv pkt from 131.108.1.2, Ethernet0, area 0.0.0.0mismatch area 0.0.0.1 in the header
R2#show log%OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 131.108.1.1, Ethernet0
(9)Stub/transit/NSSA 区域类型不匹配
这个是常常不小心会被忘记的。
R1#debug ip ospf adjOSPF adjacency events debugging is onR1#OSPF: Rcv hello from 131.108.0.1 area 1 from Ethernet0 131.108.1.2OSPF: Hello from 131.108.1.2 with mismatched Stub/Transit area option bit
R1#debug ip ospf adjOSPF adjacency events debugging is onR1#OSPF: Rcv hello from 131.108.0.1 area 1 from Ethernet0 131.108.1.2OSPF: Hello from 131.108.1.2 with mismatched NSSA option bit