交换机老出现掉线，隔几分钟后就掉线。 华为的交换机。

Question

Jan 1 2008 02:40:20 dianziyuelanshi2 %%01IFNET/4/IF_STATE(l): Interface Vlanif4
000 has turned into DOWN state.
Jan 1 2008 02:40:20 dianziyuelanshi2 %%01IFNET/4/LINK_STATE(l): Line protocol o
n interface Vlanif4000 has turned into DOWN state.
Jan 1 2008 02:40:20 dianziyuelanshi2 %%01IFNET/4/UPDOWN(l): The state of interf
ace GigabitEthernet0/0/2 was changed to DOWN.
Jan 1 2008 02:40:25 dianziyuelanshi2 %%01IFNET/4/IF_STATE(l): Interface Vlanif4
000 has turned into UP state.
Jan 1 2008 02:40:25 dianziyuelanshi2 %%01IFNET/4/LINK_STATE(l): Line protocol o
n interface Vlanif4000 has turned into UP state.
Jan 1 2008 02:40:25 dianziyuelanshi2 %%01IFNET/4/UPDOWN(l): The state of interf
ace GigabitEthernet0/0/1 was changed to UP.
Jan 1 2008 02:40:30 dianziyuelanshi2 %%01IFNET/4/IF_STATE(l): Interface Vlanif4
000 has turned into DOWN state.
Jan 1 2008 02:40:30 dianziyuelanshi2 %%01IFNET/4/LINK_STATE(l): Line protocol o
n interface Vlanif4000 has turned into DOWN state.
Jan 1 2008 02:40:30 dianziyuelanshi2 %%01IFNET/4/UPDOWN(l): The state of interf
ace GigabitEthernet0/0/1 was changed to DOWN.
Can't connect to the remote host!
<dianziyuelanshi2>
Jan 1 2008 02:41:18 dianziyuelanshi2 %%01IFNET/4/IF_STATE(l): Interface Vlanif4
000 has turned into UP state.
Jan 1 2008 02:41:18 dianziyuelanshi2 %%01IFNET/4/LINK_STATE(l): Line protocol o
n interface Vlanif4000 has turned into UP state.
Jan 1 2008 02:41:18 dianziyuelanshi2 %%01IFNET/4/UPDOWN(l): The state of interf
ace GigabitEthernet0/0/2 was changed to UP.
ndp enable

Answer 1

接口松动，接触不良？本回答被提问者采纳

Answer 2

邻机发现协议 NDP（neighbor discovery protocol） ndp（neighbor discovery protocol）是用来发现邻接点相关信息的协议。ndp运行在数据链路层，因此可以支持不同的网络层协议。
ndp用来发现直接相连的邻居信息，包括邻接设备的设备名称、软/硬件版本、连接端口等，另外还可提供设备的id、端口地址、硬件平台等信息。
支持ndp的设备都维护ndp邻居信息表，邻居信息表中的每一表项都是可以老化的，一旦老化时间到，ndp自动删除相应的邻居表项。同时，用户可以清除当前的ndp信息以重新收集邻接信息。
运行ndp的设备定时向所有激活的端口广播带有ndp数据的报文，报文中携带有效保留时间，该时间指示接收设备必须保存该更新数据的时间。接收ndp报文的设备保存报文中的信息，但不转发ndp报文。收到的信息如果与旧的信息不同，则更新ndp表中的相应数据项；如果相同，则只更新有效保留时间。
ndp主要配置包括：
1 使能/禁止系统ndp
2 使能/禁止端口ndp

缺省设置如下：ndp信息的有效保留时间为180s，ndp报文发送的时间间隔为60s。