STP导致3层接口无法正常通讯

发布时间:  2015-01-15 浏览次数:  301 下载次数:  3
问题描述

1. S7706-1与CE12800-1、CE12800-2 之间可以正常ping通

2. S7706-2与CE12800-1、CE12800-2 不能ping通

告警信息
处理过程
1.进入4台交换机,将3层虚拟端口关闭stp
[CE12800-1-GigabitEthernet0/0/2]dis this
#
interface GigabitEthernet0/0/2
port link-type access
port default vlan 100
stp disable
#
return
[CE12800-1-GigabitEthernet0/0/2]
2. 检查参与stp环路计算的端口,方法如下:
[CE12800-2-GigabitEthernet0/0/3]dis stp brief
MSTID  Port                        Role  STP State     Protection
   0    GigabitEthernet0/0/1        ROOT  FORWARDING      NONE
[CE12800-1-GigabitEthernet0/0/3]
3. 在S7706-1上面pingCE128交换机,发现网络恢复正常
<S7706-1>ping 192.168.100.1
  PING 192.168.100.1: 56  data bytes, press CTRL_C to break
    Reply from 192.168.100.1: bytes=56 Sequence=1 ttl=255 time=30 ms
    Reply from 192.168.100.1: bytes=56 Sequence=2 ttl=255 time=30 ms
    Reply from 192.168.100.1: bytes=56 Sequence=3 ttl=255 time=50 ms
    Reply from 192.168.100.1: bytes=56 Sequence=4 ttl=255 time=50 ms
    Reply from 192.168.100.1: bytes=56 Sequence=5 ttl=255 time=50 ms
  --- 192.168.100.1 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 30/42/50 ms
<S7706-1>ping 192.168.200.1
  PING 192.168.200.1: 56  data bytes, press CTRL_C to break
    Reply from 192.168.200.1: bytes=56 Sequence=1 ttl=255 time=80 ms
    Reply from 192.168.200.1: bytes=56 Sequence=2 ttl=255 time=30 ms
    Reply from 192.168.200.1: bytes=56 Sequence=3 ttl=255 time=60 ms
    Reply from 192.168.200.1: bytes=56 Sequence=4 ttl=255 time=50 ms
    Reply from 192.168.200.1: bytes=56 Sequence=5 ttl=255 time=60 ms
  --- 192.168.200.1 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 30/56/80 ms
<S7706-1>
4. 登录第二台7706交换机,检查网络已恢复正常
<s7706-2>ping 192.168.101.1
  PING 192.168.101.1: 56  data bytes, press CTRL_C to break
    Reply from 192.168.101.1: bytes=56 Sequence=1 ttl=255 time=30 ms
    Reply from 192.168.101.1: bytes=56 Sequence=2 ttl=255 time=50 ms
    Reply from 192.168.101.1: bytes=56 Sequence=3 ttl=255 time=50 ms
  --- 192.168.101.1 ping statistics ---
    3 packet(s) transmitted
    3 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 30/43/50 ms
<s7706-2>ping 192.168.201.1
  PING 192.168.201.1: 56  data bytes, press CTRL_C to break
    Reply from 192.168.201.1: bytes=56 Sequence=1 ttl=255 time=90 ms
    Reply from 192.168.201.1: bytes=56 Sequence=2 ttl=255 time=50 ms
    Reply from 192.168.201.1: bytes=56 Sequence=3 ttl=255 time=60 ms
    Reply from 192.168.201.1: bytes=56 Sequence=4 ttl=255 time=30 ms
    Reply from 192.168.201.1: bytes=56 Sequence=5 ttl=255 time=30 ms
  --- 192.168.201.1 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 30/52/90 ms
<s7706-2>
根因
设备上都开启了mstp协议,mstp将交换机互联的接口误认为是存在环路,导致CE12800-2的端口出现DISCARDING状态,无法进行正常通讯
<CE12800-2>dis stp brief
MSTID  Port                        Role  STP State     Protection
   0    GigabitEthernet0/0/1        ALTE  DISCARDING      NONE
   0    GigabitEthernet0/0/2        ROOT  FORWARDING      NONE
   0    GigabitEthernet0/0/3        ALTE  DISCARDING      NONE
建议与总结
在交换机上面配置时,如果有配置为3层虚拟接口的端口时,有必要将端口的stp关闭,以免对3层网络造成不通的情况。

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