[0003]: %OSPF-6-INFO: OSPF-18: Full neighbor 192.168.16.54 event: Sequence Mi...

3 P1 r% l  e9 G2 M3 oMay 11 16:02:49: [0003]: %OSPF-6-INFO: OSPF-18: Full neighbor 192.168.16.54 event: Sequence Mismatch
May 11 16:02:49: [0003]: %OSPF-6-INFO: OSPF-18: Neighbor 192.168.16.54 fell from Full state to ExStart state
这个 是什么情况
1 [0 D3 C2 \- S! s为什么会 Full 变成 Exstrat的
请教一下
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  t' I' A3 R0 G9 R本问题来自论坛QQ群 2258097(免费解答学习/工作中的问题)

配置不一致，邻接关系无法建立。

MTU不对或者序号出错了 重启协议

May 11 16:02:49: [0003]: %OSPF-6-INFO: OSPF-18: Full neighbor 192.168.16.54 event: Sequence Mismatch
Sequence Mismatch 有機會是Timer不對導致收發OSPF packets有時間差, OSPF以為收不到packet就restart service了

“May 11 16:02:49: [0003]: %OSPF-6-INFO: OSPF-18: Full neighbor 192.168.16.54 event: Sequence Mismatch:
  C1 H+ e5 k% _: Y- C; kMay 11 16:02:49: [0003]: %OSPF-6-INFO: OSPF-18: Neighbor 192.168.16.54 fell from Full state to ExStart state” 这个貌似曾经是HCIE的一道面试题，原理是由于OSPF的LSDB中有一个表示字段为Sequence字段会增加得很快，造成Sequence字段不匹配，这样会导致OSPF的LSA频繁地老化和产生，进而会导致Full state to ExStart state，导致网络不稳定。

Sequence两端不一致，导致邻居状态从FULL变为ExStart state。