Shulou(Shulou.com)06/01 Report--

First of all, when you encounter a LAN link failure, troubleshoot from external devices:

PC-- > Line-- > switch

Enter the PC interface

PC0

PC1

After checking, it is found that the subnetting is incorrect: it is changed to the same subnet network segment.

The subnet mask is changed to: 255.255.255.0

Let's start checking the switch.

Switch0

View the current running configuration in the user interface:

SW1#show running-config

Spanning-tree mode pvst

!

Interface FastEthernet0/1

!

Interface FastEthernet0/23

Switchport trunk allowed vlan 1-9, 11-1005

Switchport mode trunk

!

After summarizing the above configuration, the following information is obtained:

1 port connected to the computer is not configured with vlan 10 access mode

Port 23 does not allow vlan10 to pass

Configured:

Interface FastEthernet0/1

Switchport access vlan 10

Switchport mode access

Interface FastEthernet0/23

Switchport mode trunk

Move on to the next one.

Switch 1

Spanning-tree mode rapid-pvst

!

Interface FastEthernet0/22

Channel-protocol lacp

Channel-group 1 mode passive

!

Interface FastEthernet0/23

Switchport trunk allowed vlan 1-9, 11-1005

!

Interface FastEthernet0/24

Channel-protocol lacp

Channel-group 1 mode passive

Interface Port-channel 1

Spanning-tree guard root

After summarizing the above configuration, the following information is obtained:

Spanning tree mode is pvst

The 23-port trunk mode connected to switch 0 does not allow vlan 10 to pass

Port 22lap 24 runs aggregate link mode lacp port mode is passive

Interface Port Channel 1 spanning Tree Root Protection

This switch is configured with root guard, and the topic requires switch 2 as the root switch.

In order not to do repetitive work, I decided to check switch 2 before configuring it.

Switch 2

Spanning-tree mode pvst

Spanning-tree vlan 10 priority 0

!

Interface FastEthernet0/1

Shutdown

Interface FastEthernet0/22

Channel-protocol pagp

Channel-group 2 mode auto

Switchport mode trunk

Interface FastEthernet0/24

Channel-protocol pagp

Channel-group 2 mode auto

Switchport mode trunk

Interface Port-channel 2

Switchport mode trunk

After summarizing the above configuration, the following information is obtained:

No VLAN 10

Spanning tree mode PVST

Vlan 10 has a priority of 0 (the smaller the number, the higher the priority)

Connection PC port 1 is closed

Port 22am 24 is configured for aggregate link PAGP (Cisco proprietary) mode

Channel group 2 automatic mode turns on trunk mode

Interface Port Channel 2 is set to trunk mode

By comparing switch 1 and switch 2, the following questions are obtained:

1. The data can not be transmitted normally due to the different aggregation link mode of 22lap24.

Switch3 is required as the root switch, but switch2 is protected by root.

Let's start the configuration:

First of all:

Open port 1 of switch3

Turn off the root protection of switch2

3. The channel group is set to the same channel group and changed to a group at the same time.

4. Set the aggregation links to trunk and turn them on.

Configuration after change:

Switch 1

Spanning-tree mode pvst

!

Interface FastEthernet0/22

Channel-protocol lacp

Channel-group 1 mode active

Switchport mode trunk

!

Interface FastEthernet0/23

!

Interface FastEthernet0/24

Channel-protocol lacp

Channel-group 1 mode active

Switchport mode trunk

!

Interface Port-channel 1

Switchport mode trunk

!

Switch3

Spanning-tree mode pvst

Spanning-tree vlan 10 priority 0

!

Interface FastEthernet0/1

Switchport access vlan 10

Switchport mode access

Interface FastEthernet0/22

Channel-protocol lacp

Channel-group 1 mode active

Switchport mode trunk

!

Interface FastEthernet0/23

!

Interface FastEthernet0/24

Channel-protocol lacp

Channel-group 1 mode active

Switchport mode trunk

Interface Port-channel 1

Switchport mode trunk

=

Connectivity testing:

Root test

Switch3

SW3#show spanning-tree

VLAN0010

Spanning tree enabled protocol ieee

Root ID Priority 10

Address 0009.7C27.2B0A

This bridge is the root

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 10 (priority 0 sys-id-ext 10)

Address 0009.7C27.2B0A

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Aging Time 20

Interface Role Sts Cost Prio.Nbr Type

Fa0/1 Desg FWD 19 128.1 P2p

Fa0/24 Desg FWD 19 128.24 P2p

Fa0/22 Desg FWD 19 128.22 P2p

Po1 Desg FWD 9 128.28 Shr

Shows that this switch is the switch3

Done.

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