Tài liệu Troubleshooting VTP (Troubleshooting LAN Switches) docx

1-5 Semester 8 Internetwork Troubleshooting v1.0 - Lab 5.1.3 Copyright  2001, Cisco Systems, Inc.
Lab 5.1.3 Troubleshooting VTP (Troubleshooting LAN Switches)
Fa 2/3 Fa 0/12
Fa 0/1
Trunk 802.1q
Crossover Connection
ALSwitch
2900XL-Ent
4006 L3
VLAN 10 Client


Objective
VLAN Trunk Protocol (VTP) reduces administration in switched networks.
When you configure a new VLAN on one VTP server, the VLAN is distributed
through all switches in the domain. This reduces the need of configuring the
same VLAN everywhere. VTP is a Cisco-proprietary protocol that is available
on most of the Cisco Catalyst Family products. In this lab you will troubleshoot
some basic VLAN trunking problems with VTP (VLAN Trunking Protocol).
Scenario
This is not part of the International Travel Agency network.
As the Enterprise Network Administrator, you have a large switched network
that is all in the same VTP domain. Your network administrator added a new
2900XL-Enterprise switch to the network. The first connected client to the new
switch is from the Accounting Department (VLAN 10). He indicates immediately
that he is not able to reach any network resources. The administrator indicated
that he did issue the command “switchport access vlan 10” on FastEthernet
port 0/1, which is the port the Accounting member is connected to, and also
verified that both the links (FastEthernet 0/1 and FastEthernet 0/12) indicate a
green connection light on the 2900. FastEthernet 0/12 is designated as the up-

link trunking port.
Lab Tasks
Cable the lab as shown in the diagram.
Clear the DLRouter configuration using the following commands:
Router#erase start
Erasing the nvram filesystem will remove all files! Continue? [confirm]y[OK]
Erase of nvram: complete
Router#reload
Proceed with reload? [confirm]y

Clear the DLSwitch configuration using the following commands:

2-5 Semester 8 Internetwork Troubleshooting v1.0 - Lab 5.1.3 Copyright  2001, Cisco Systems, Inc.
Console> (enable) clear config all
This command will clear all configuration in NVRAM.
This command will cause ifIndex to be reassigned on the next system startup.
Do you want to continue (y/n) [n]? y

2001 Jun 16 12:29:45 %PAGP-5-PORTFROMSTP:Port 2/1 left bridge port 2/1
.2001 Jun 16 12:29:45 %PAGP-5-PORTFROMSTP:Port 2/2 left bridge port 2/2
2001 Jun 16 12:29:45 %PAGP-5-PORTFROMSTP:Port 2/3 left bridge port 2/3


Console> (enable) reset
This command will reset the system.
Do you want to continue (y/n) [n]? y

Clear the ALSwitch configuration and VLAN database using the following com-
mands:
ALSwitch#clear start

Erasing the nvram filesystem will remove all files! Continue? [confirm]y[OK]
Erase of nvram: complete
ALSwitch#delete vlan.dat
Delete filename [vlan.dat]?
Delete flash:vlan.dat? [confirm]y
ALSwitch#reload
Proceed with reload? [confirm]y

Load the file called Lab5-1-3-DLSwitchBrokenConfig.txt into the DLSwitch
switch.
Load the file called Lab5-1-3-ALSwitchBrokenConfig.txt into the ALSwitch
switch.
Step 1
Define your problem.
On the DLSwitch, execute the following commands:
DLSwitch> (enable) show vlan
VLAN Name Status IfIndex Mod/Ports, Vlans

1 default active 6 1/1-2
2/1-2,2/7-34
10 Accounting active 11 2/4
20 Marketing active 12 2/5
30 Engineering active 13 2/6
1002 fddi-default active 7
1003 token-ring-default active 10
1004 fddinet-default active 8
1005 trnet-default active 9


VLAN Type SAID MTU Parent RingNo BrdgNo Stp BrdgMode Trans1 Trans2

1 enet 100001 1500 - - - - - 0 0
10 enet 100010 1500 - - - - - 0 0
20 enet 100020 1500 - - - - - 0 0
30 enet 100030 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
1003 trcrf 101003 1500 - - - - - 0 0
1004 fdnet 101004 1500 - - - - - 0 0
1005 trbrf 101005 1500 - - - ibm - 0 0


DLSwitch> (enable) show trunk

3-5 Semester 8 Internetwork Troubleshooting v1.0 - Lab 5.1.3 Copyright  2001, Cisco Systems, Inc.
* - indicates vtp domain mismatch
Port Mode Encapsulation Status Native vlan

2/3 on dot1q trunking 1

Port Vlans allowed on trunk

2/3 1-1005

Port Vlans allowed and active in management domain

2/3 1,10,20,30

Port Vlans in spanning tree forwarding state and not pruned

2/3 1,10,20,30

DLSwitch> (enable)

On the ALSwitch, execute the following commands:
ALSwitch#show ip interface brief
Any interface listed with OK? value "NO" does not have a valid configuration

Interface IP-Address OK? Method Status Protocol
VLAN1 unassigned NO unset up up
FastEthernet0/1 unassigned YES unset down down
FastEthernet0/2 unassigned YES unset down down
FastEthernet0/3 unassigned YES unset down down
FastEthernet0/4 unassigned YES unset down down
FastEthernet0/5 unassigned YES unset down down
FastEthernet0/6 unassigned YES unset down down
FastEthernet0/7 unassigned YES unset down down
FastEthernet0/8 unassigned YES unset down down
FastEthernet0/9 unassigned YES unset down down
FastEthernet0/10 unassigned YES unset down down
FastEthernet0/11 unassigned YES unset down down
FastEthernet0/12 unassigned YES unset up up

ALSwitch#show vlan
VLAN Name Status Ports

1 default active Fa0/2, Fa0/3, Fa0/4, Fa0/5,
Fa0/6, Fa0/7, Fa0/8, Fa0/9,
Fa0/10, Fa0/11, Fa0/12
10 VLAN0010 active Fa0/1
1002 fddi-default active
1003 token-ring-default active

1004 fddinet-default active
1005 trnet-default active

Describe the problem. (Hint: Compare the vlans between the ALSwitch and
DLSwitch.)


Step 2
Gather the Facts.
On the ALSwitch, execute the following commands:

4-5 Semester 8 Internetwork Troubleshooting v1.0 - Lab 5.1.3 Copyright  2001, Cisco Systems, Inc.
ALSwitch#show vtp counters
VTP statistics:
Summary advertisements received : 0
Subset advertisements received : 0
Request advertisements received : 0
Summary advertisements transmitted : 0
Subset advertisements transmitted : 0
Request advertisements transmitted : 0
Number of config revision errors : 0
Number of config digest errors : 0
Number of V1 summary errors : 0


VTP pruning statistics:

Trunk Join Transmitted Join Received Summary advts received from
non-pruning-capable device

ALSwitch#show vtp status
VTP Version : 2
Configuration Revision : 1
Maximum VLANs supported locally : 68
Number of existing VLANs : 6
VTP Operating Mode : Server
VTP Domain Name :
VTP Pruning Mode : Disabled
VTP V2 Mode : Disabled
VTP Traps Generation : Disabled
MD5 digest : 0x3B 0xBF 0x2D 0x08 0x49 0x5E 0x7E 0x73
Configuration last modified by 0.0.0.0 at 3-1-93 00:01:21
ALSwitch#

On the DLSwitch, execute the following commands:
DLSwitch> (enable) show vtp statistics
VTP statistics:
summary advts received 0
subset advts received 0
request advts received 0
summary advts transmitted 1
subset advts transmitted 1
request advts transmitted 0
No of config revision errors 0
No of config digest errors 0


VTP pruning statistics:

Trunk Join Transmitted Join Received Summary advts received from GVRP PDU

non-pruning-capable device Received

2/3 0 0 0 0
DLSwitch> (enable) show vtp domain
Domain Name Domain Index VTP Version Local Mode Password

corp 1 2 server configured

Vlan-count Max-vlan-storage Config Revision Notifications

8 1023 6 disabled

Last Updater V2 Mode Pruning PruneEligible on Vlans

0.0.0.0 disabled disabled 2-1000
DLSwitch> (enable)


5-5 Semester 8 Internetwork Troubleshooting v1.0 - Lab 5.1.3 Copyright  2001, Cisco Systems, Inc.
Step 3
Write down your observations for the ALSwitch and the DLSwitch.


Step 4
List the possible causes of this problem.


Step 5
Create an Action Plan to fix the problem.

Step 6
Implement the Action Plan.
Step 7
Observe the Results of the Action Plan.
Issue the same commands in Step 2 and verify that the output has changed.
Verify that the trunking is now operational.
Step 8
Document your work.