09-21-2013 04:25 AM - edited 03-07-2019 03:36 PM
Hi,
I have one L2 switch 2960 switch which in not updating the Vlan info from Core Switch. I have configure trunk from Core switch to this L2 switch and i am able connet the switch. the only problem is the switch is not updating the vlan database from Core switch.
Can any one help me what shoud i do the update the vlan information in to L2 2960 switch.
Please find the 2960 switch details.
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 50 WS-C2960-48TC-L 12.2(25)SEE2 C2960-LANBASE-M
Please find the VTP status of both switch.
VTP status of Switch 2960.
2ndfloor#sh vtp status
VTP Version : 2
Configuration Revision : 0
Maximum VLANs supported locally : 255
Number of existing VLANs : 6
VTP Operating Mode : Client
VTP Domain Name :
VTP Pruning Mode : Disabled
VTP V2 Mode : Enabled
VTP Traps Generation : Disabled
MD5 digest : 0xDF 0xE4 0x18 0x3F 0xBB 0xCE 0x47 0x7D
Configuration last modified by 10.10.100.14 at 3-1-93 00:03:06
2ndfloor#sh int trunk
Port Mode Encapsulation Status Native vlan
Fa0/48 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa0/48 1-4094
Port Vlans allowed and active in management domain
Fa0/48 1,10
Port Vlans in spanning tree forwarding state and not pruned
Fa0/48 1,10
interface FastEthernet0/48
switchport mode trunk
end
Now find the below details of Core Switch(L3 switch).
CORE_SWITCH#sh vtp status
VTP Version : running VTP2
Configuration Revision : 170
Maximum VLANs supported locally : 1005
Number of existing VLANs : 66
VTP Operating Mode : Server
VTP Domain Name :
VTP Pruning Mode : Disabled
VTP V2 Mode : Enabled
VTP Traps Generation : Disabled
MD5 digest : 0xA3 0xB7 0x83 0x64 0x22 0x66 0x66 0xFC
Configuration last modified by 10.10.10.1 at 7-18-12 09:05:18
Local updater ID is 10.10.10.1 on interface Vl1 (lowest numbered VLAN interface found)
Port Mode Encapsulation Status Native vlan
Fa6/17 on 802.1q trunking 1
interface FastEthernet6/17
switchport trunk encapsulation dot1q
switchport mode trunk
no logging event link-status
spanning-tree bpduguard disable
If you see the both configuration the Configuration Revision is not updating in L2 switch.
Can any tell me wt should i do the update the Configuration Revision in L2 switch.
Regards
Prashant
09-21-2013 06:10 AM
Did you leave the vtp domain name out on purpose, or is it truly missing in the config? If it's missing, add a domain name and see if that fixes your issue...
HTH,
John
**** Please rate all useful posts ****
09-21-2013 09:23 AM
Agree to with John.
For VTP to work you need to configure the following parameters:
1- VTP Domain Name
2- Make sure the connected interface is trunk port and vlans are been allowed.
3- Make sure the edge devices connecting to the core or not configured transparent switch.
4- If you are planning to configure the VTP-password then it should be same on all the switches,
Please check the link below:
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml
HTH
REgards
Inayath
09-23-2013 12:23 AM
Team,
I know VTP domain name is requerird. I removed the name purposly. Now Please let know why it is not updating the Configuration Revision in L2 switch. I have tried all possibilities. Please let me know if I am missing something.
You can see my configuration which i have alredy shared with you.
Regards
Prashant
09-23-2013 12:51 AM
Hi Prashant,
Have you tried adding and removing any new vlan on the VTP server recently? If not try adding a dummy vlan and verify if that helps.
You can debug VTP using the following "debug sw-vlan vtp events" or "debug sw-vlan vtp events packets" and verify what is going on and background.
Hope that helps.
Regards
Najaf
09-23-2013 01:11 AM
Okay Let me try to explain you the behaviour:
Here are the few things which I can see in your issue:
==========================================
1- You Setup doesnt have the VTP domain name:
AS you know that Summary advertisements inform adjacent Catalysts of the current VTP domain name and the configuration revision number.
When the switch receives a summary advertisement packet, the switch compares the VTP domain name to its own VTP domain name. If the name is different, the switch simply ignores the packet. If the name is the same, the switch then compares the configuration revision to its own revision. If its own configuration revision is higher or equal, the packet is ignored. If it is lower, an advertisement request is sent.
2- I could see the Conf reg is 170 on the server and 0 on the layer 2 switch.(This assumes that the Layer 2 switch might have just changed to vtp mode client or someone deleted the domain name and left it blank) .
3- Though you have the trunk ports configured between these devices and assuming that it works fine still you would not see the VTP infomration been updated from Server to the Client.
Next Action:
==========
- To avoid more troubleshooting check the following things;
1- Just try to create vlan on the server(Core-Switch) and check if the conf revision number gets increased to 171 ? If yes then the server is working fine.
2- Configure the domain name on CORE_Switch(Configuring the domain name -NOTE- Configuring the domain name will clear the config revision number to 0 but all your vlans would still be available.)
3-Configure the domain name to match the same as CORE-Switch on Layer 2 -2950 switch.
4- Now try to create the Vlan on the server and you should see the update populating over to Layer 2 switch.
Hope this should solve your query.
HTH
Regards
Inayath
09-24-2013 05:28 AM
Hi Team,
Thanks for your help. Now the issue has been resolved. I did not put the VTP password because of L2 switch is not updating the Vlan data base form L3 core switch.
Regards
Prashant
09-24-2013 05:31 AM
Prashant,
Thnks for the update .Glad to hear the issue has been resolved.
Coming down the VTP Password its always good to configure the password in the vtp domain so that everything should be reachable and have the proper MD5 calculation.
Hope this thread has helped you. If no further query is required I request you to kindly mark this thread as answered rather than leaving it to be unanswered.
Thanks
Regards
Inayath
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