LS ACK packet errors:

0 : Neighbor state low 0 : Bad ack

0 : Duplicate ack 0 : Unknown LSA type LS REQ packet errors:

0 : Neighbor state low 0 : Empty request 0 : Bad request

LS UPD packet errors:

0 : Neighbor state low 0 : Newer self-generate LSA 0 : LSA checksum bad 0 : Received less recent LSA 0 : Unknown LSA type Opaque errors:

0 : 9-out of flooding scope 0 : 10-out of flooding scope 0 : 11-out of flooding scope

Retransmission for packet over Limitation errors:

0 : Number for DD Packet 0 : Number for Update Packet 0 : Number for Request Packet Receive Grace LSA errors:

0 : Number of invalid LSAs 0 : Number of policy failed LSAs 0 : Number of wrong period LSAs Configuration errors: 0 : Tunnel cost mistake

0 : The network type of the neighboring interface is not consistent. A.Router ID 冲突

B.Hello 时间间隔和Dead 时间间隔不一致 C.验证类型不一致 D.网络掩码不一致

116.OSPF 邻居无法建立，display ospf error 给出如下信息，有可能的原因是 [RTB]display ospf error

OSPF Process 1 with Router ID 2.2.2.2 OSPF error statistics: General packet errors:

0 : IP: received my own packet 0 : Bad packet 0 : Bad version 0 : Bad checksum

0 : Bad area id 0 : Drop on unnumbered interface 0 : Bad virtual link 0 : Bad authentication type 3 : Bad authentication key 0 : Packet too small 0 : Packet size > ip length 0 : Transmit error 0 : Interface down 0 : Unknown neighbor HELLO packet errors:

0 : Netmask mismatch 0 : Hello timer mismatch

0 : Dead timer mismatch 0 : Extern option mismatch 0 : Router id confusion 0 : Virtual neighbor unknown 0 : NBMA neighbor unknown DD packet errors:

0 : Neighbor state low 0 : Router id confusion

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0 : Extern option mismatch 0 : Unknown LSA type 0 : MTU option mismatch LS ACK packet errors:

0 : Neighbor state low 0 : Bad ack

0 : Duplicate ack 0 : Unknown LSA type LS REQ packet errors:

0 : Neighbor state low 0 : Empty request 0 : Bad request

LS UPD packet errors:

0 : Neighbor state low 0 : Newer self-generate LSA 0 : LSA checksum bad 0 : Received less recent LSA 0 : Unknown LSA type Opaque errors:

0 : 9-out of flooding scope 0 : 10-out of flooding scope 0 : 11-out of flooding scope

Retransmission for packet over Limitation errors:

0 : Number for DD Packet 0 : Number for Update Packet 0 : Number for Request Packet Receive Grace LSA errors:

0 : Number of invalid LSAs 0 : Number of policy failed LSAs 0 : Number of wrong period LSAs Configuration errors: 0 : Tunnel cost mistake

0 : The network type of the neighboring interface is not consistent. A.Router ID 冲突 B.区域ID 不匹配 C.验证密码不一致 D.验证类型不一致

117.OSPF 邻居无法建立，display ospf error 给出如下信息，有可能的原因是 [RTB]display ospf error

OSPF Process 1 with Router ID 2.2.2.2 OSPF error statistics: General packet errors:

0 : IP: received my own packet 0 : Bad packet 0 : Bad version 0 : Bad checksum

7 : Bad area id 0 : Drop on unnumbered interface 0 : Bad virtual link 0 : Bad authentication type 0 : Bad authentication key 0 : Packet too small 0 : Packet size > ip length 0 : Transmit error 0 : Interface down 0 : Unknown neighbor HELLO packet errors:

0 : Netmask mismatch 0 : Hello timer mismatch

0 : Dead timer mismatch 0 : Extern option mismatch 9 : Router id confusion 0 : Virtual neighbor unknown 0 : NBMA neighbor unknown

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DD packet errors:

0 : Neighbor state low 0 : Router id confusion

0 : Extern option mismatch 0 : Unknown LSA type 0 : MTU option mismatch LS ACK packet errors:

0 : Neighbor state low 0 : Bad ack

0 : Duplicate ack 0 : Unknown LSA type LS REQ packet errors:

0 : Neighbor state low 0 : Empty request 0 : Bad request

LS UPD packet errors:

0 : Neighbor state low 0 : Newer self-generate LSA 0 : LSA checksum bad 0 : Received less recent LSA 0 : Unknown LSA type Opaque errors:

0 : 9-out of flooding scope 0 : 10-out of flooding scope 0 : 11-out of flooding scope

Retransmission for packet over Limitation errors:

0 : Number for DD Packet 0 : Number for Update Packet 0 : Number for Request Packet Receive Grace LSA errors:

0 : Number of invalid LSAs 0 : Number of policy failed LSAs 0 : Number of wrong period LSAs Configuration errors: 0 : Tunnel cost mistake

0 : The network type of the neighboring interface is not consistent. A.Hello 时间间隔和Dead 时间间隔不一致 B.区域ID 不匹配 C.网络掩码不一致 D.验证类型不一致

118.OSPF 邻居无法建立，display ospf error 给出如下信息，有可能的原因是 [RTB]display ospf error

OSPF Process 1 with Router ID 2.2.2.2 OSPF error statistics: General packet errors:

0 : IP: received my own packet 0 : Bad packet 0 : Bad version 0 : Bad checksum

0 : Bad area id 0 : Drop on unnumbered interface 0 : Bad virtual link 0 : Bad authentication type 0 : Bad authentication key 0 : Packet too small 0 : Packet size > ip length 0 : Transmit error 0 : Interface down 0 : Unknown neighbor HELLO packet errors:

9 : Netmask mismatch 0 : Hello timer mismatch

0 : Dead timer mismatch 0 : Extern option mismatch

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0 : Router id confusion 0 : Virtual neighbor unknown 0 : NBMA neighbor unknown DD packet errors:

0 : Neighbor state low 0 : Router id confusion

0 : Extern option mismatch 0 : Unknown LSA type 0 : MTU option mismatch LS ACK packet errors:

0 : Neighbor state low 0 : Bad ack

0 : Duplicate ack 0 : Unknown LSA type LS REQ packet errors:

0 : Neighbor state low 0 : Empty request 0 : Bad request

LS UPD packet errors:

0 : Neighbor state low 0 : Newer self-generate LSA 0 : LSA checksum bad 0 : Received less recent LSA 0 : Unknown LSA type Opaque errors:

0 : 9-out of flooding scope 0 : 10-out of flooding scope 0 : 11-out of flooding scope

Retransmission for packet over Limitation errors:

0 : Number for DD Packet 0 : Number for Update Packet 0 : Number for Request Packet Receive Grace LSA errors:

0 : Number of invalid LSAs 0 : Number of policy failed LSAs 0 : Number of wrong period LSAs Configuration errors: 0 : Tunnel cost mistake

0 : The network type of the neighboring interface is not consistent. A.Router ID 冲突 B.网络掩码不一致 C.验证密码不一致 D.验证类型不一致

119.下面关于运行在按需链路上的OSPF 描述错误的是： A.在按需链路上发送HELLO 时，要设置DC 位

B.在建立邻接关系之前，每隔120s 间隔发送一次HELLO 报文，用于检测邻居

C.在建立邻接关系之后，不再发送HELLO 报文，即始终认为对端邻居处于活动状态 D.在建立邻接关系之后，LSA 每隔30min 需要进行一次刷新

120.下面关于LSA age 字段描述正确的是：（请选择2 个答案）

A.LSA age 的单位为秒，在LSDB 中的LSA 的LS age 随时间增长而减少 B.LSA age 的单位为秒，在LSDB 中的LSA 的LS age 随时间增长而增长

C.如果一条LSA 的LS age 达到了LSRefreshTime(30min)，这条LSA 的生产者需要重新生成一个该LSA的实例

D.如果一条LSA 的LS age 达到了LSRefreshTime(30min)，任意一台路由器都可以对这条LSA 重新生成一个该LSA 的实例

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