VLAN Trunking + VPT

Answered Question

Hi,

I have two 3750 switch connected to eatch other.


There's a 802.1Q trunk between the two switchs. There's also VTP and Spantree activated on those switch. The two switch are in the same VTP domain, and they are server.


I added a VLAN 185 on the first 3750, and it did not reply on the second.


So I added manually in the second 3750 the VLAN 185.


I've configured an interface VLAN185 in both switchs, in the same network.

EX :

SWITCH1 : Int vlan185 ip : 10.10.1.1 255.255.255.0

SWITCH2 :Int vlan185 ip : 10.10.1.2 255.255.255.0


MY PROBLEM :

I'm not able to ping on both side anything in the vlan 185.


Tanks a lot.


Shera


Correct Answer by Kevin Dorrell about 8 years 10 months ago

Mmm. That is strange because it looks like the MD5 digest is different on the two switches. Sorry to insist, but are you sure there is not a VTP password? I have a synchronised domain, and I have the same MD5 digest on both server switches.


I presume these two switches are directly connected together via 3750-2 G1/0/25 to 3750-1 don't-know which port. Perhaps it would be useful to see the configs of the two ports connecting them together and a show cdp neighbor G1/0/25 detail.


Kevin Dorrell

Luxembourg


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mohammedmahmoud Thu, 04/24/2008 - 11:55

Hi Shera,


First we need to make sure that the trunk between the switches is operational and thus please post a "show interfaces trunk", second we need to check the VTP status and thus please post a "show vtp status".


BR,

Mohammed Mahmoud.

Hi,


Here's the first 3750

3750-1-10.10.10.110#sh interfaces trunk


Port Mode Encapsulation Status Native vlan

Gi1/0/21 on 802.1q trunking 1

Gi1/0/22 on 802.1q trunking 1

Gi1/0/23 on 802.1q trunking 1

Gi1/0/24 on 802.1q trunking 1

Gi1/0/25 on 802.1q trunking 1


Port Vlans allowed on trunk

Gi1/0/21 1-4094

Gi1/0/22 1-4094

Gi1/0/23 1-4094

Gi1/0/24 1-4094

Gi1/0/25 1-4094


Port Vlans allowed and active in management domain

Gi1/0/21 1-2,8,10,16,161-162,167,185,192

Gi1/0/22 1-2,8,10,16,161-162,167,185,192

Gi1/0/23 1-2,8,10,16,161-162,167,185,192

Gi1/0/24 1-2,8,10,16,161-162,167,185,192

Gi1/0/25 1-2,8,10,16,161-162,167,185,192


Port Vlans in spanning tree forwarding state and not pruned

Gi1/0/21 1-2,8,10,16,161-162,167,185,192

Gi1/0/22 1-2,8,10,16,161-162,167,185,192

Gi1/0/23 1-2,8,10,16,161-162,167,185,192

Gi1/0/24 1-2,8,10,16,161-162,167,185,192

Gi1/0/25 1-2,8,10,16,161-162,167,185,192


SSM-3750-001#sh vtp status

VTP Version : 2

Configuration Revision : 9

Maximum VLANs supported locally : 1005

Number of existing VLANs : 14

VTP Operating Mode : Server

VTP Domain Name : CHBE

VTP Pruning Mode : Disabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0xBB 0x9E 0x23 0x70 0x2C 0x32 0x6E 0x05

Configuration last modified by 10.10.10.140 at 4-15-08 13:53:41

Local updater ID is 10.10.10.140 on interface Vl1 (lowest numbered VLAN interface




3750-2-10.10.10.140#sh int trunk


Port Mode Encapsulation Status Native vlan

Gi1/0/1 auto n-802.1q trunking 1

Gi1/0/17 auto n-802.1q trunking 1

Gi1/0/24 auto n-802.1q trunking 1

Gi1/0/25 on 802.1q trunking 1

Gi1/0/26 on 802.1q trunking 1

Gi1/0/28 on 802.1q trunking 1


Port Vlans allowed on trunk

Gi1/0/1 1-4094

Gi1/0/17 1-4094

Gi1/0/24 1-4094

Gi1/0/25 1-4094

Gi1/0/26 1-4094

Gi1/0/28 1-4094


Port Vlans allowed and active in management domain

Gi1/0/1 1-2,8,10,16,161-162,167,185,192

Gi1/0/17 1-2,8,10,16,161-162,167,185,192

Gi1/0/24 1-2,8,10,16,161-162,167,185,192

Gi1/0/25 1-2,8,10,16,161-162,167,185,192


Port Vlans allowed and active in management domain

Gi1/0/26 1-2,8,10,16,161-162,167,185,192

Gi1/0/28 1-2,8,10,16,161-162,167,185,192


Port Vlans in spanning tree forwarding state and not pruned

Gi1/0/1 1-2,8,10,16,161-162,167,185,192

Gi1/0/17 1-2,8,10,16,161-162,167,185,192

Gi1/0/24 1-2,8,10,16,192

Gi1/0/25 1-2,8,10,16,161-162,167,185,192

Gi1/0/26 1-2,8,10,16,161-162,167,185,192

Gi1/0/28 1-2,8,10,16,161-162,167,185,192


PACS_3750-01#sh vtp status

VTP Version : 2

Configuration Revision : 9

Maximum VLANs supported locally : 1005

Number of existing VLANs : 14

VTP Operating Mode : Server

VTP Domain Name : CHBE

VTP Pruning Mode : Disabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0x1C 0x34 0x71 0xAF 0xD5 0x1F 0xC4 0x8A

Configuration last modified by 10.10.10.110 at 4-15-08 12:46:46

Local updater ID is 10.10.10.110 on interface Vl1 (lowest numbered VLAN interface found)


Maybe this will help :


3750-2-10.10.10.140#sh spanning-tree root priority

VLAN0001 4097

VLAN0002 8194

VLAN0008 8200

VLAN0010 4106

VLAN0016 8208

VLAN0161 32768

VLAN0162 32768

VLAN0167 32768

VLAN0185 32768

VLAN0192 4288


#sh spanning-tree root port

VLAN0001 GigabitEthernet1/0/25

VLAN0002 This bridge is root

VLAN0008 This bridge is root

VLAN0010 This bridge is root

VLAN0016 This bridge is root

VLAN0161 GigabitEthernet1/0/25

VLAN0162 GigabitEthernet1/0/25

VLAN0167 GigabitEthernet1/0/25

VLAN0185 GigabitEthernet1/0/24

VLAN0192 This bridge is root


3750-1-10.10.10.110#sh spanning-tree root priority

VLAN0001 4097

VLAN0002 4098

VLAN0008 4104

VLAN0010 4106

VLAN0016 4112

VLAN0161 32768

VLAN0162 32768

VLAN0167 32768

VLAN0185 32768

VLAN0192 4288


#sh spanning-tree root port

VLAN0001 This bridge is root

VLAN0002 This bridge is root

VLAN0008 This bridge is root

VLAN0010 GigabitEthernet1/0/26

VLAN0016 This bridge is root

VLAN0161 GigabitEthernet1/0/25

VLAN0162 GigabitEthernet1/0/25

VLAN0167 GigabitEthernet1/0/25

VLAN0185 GigabitEthernet1/0/25

VLAN0192 GigabitEthernet1/0/26

mohammedmahmoud Thu, 04/24/2008 - 13:45

Hi,


Sorry for the delay, can you please post a "show vtp password", "sh ip int brief" and "show ip route".


BR,

Mohammed Mahmoud.

mohammedmahmoud Thu, 04/24/2008 - 15:02

Shera,


I've to go for now, to guide you in the logical directions, please check the VTP password on both switches, please make sure that the SVI interfaces are up/up and that ip routing is enabled.


BR,

Mohammed Mahmoud.

hi,


Here it goes with VTP counters


3750#sh vtp counters

VTP statistics:

Summary advertisements received : 1013

Subset advertisements received : 11

Request advertisements received : 0

Summary advertisements transmitted : 971

Subset advertisements transmitted : 11

Request advertisements transmitted : 2

Number of config revision errors : 0

Number of config digest errors : 0

Number of V1 summary errors : 0


the other switch


3750-01#sh vtp counters

VTP statistics:

Summary advertisements received : 986

Subset advertisements received : 12

Request advertisements received : 2

Summary advertisements transmitted : 1027

Subset advertisements transmitted : 14

Request advertisements transmitted : 1

Number of config revision errors : 0

Number of config digest errors : 0

Number of V1 summary errors : 0

Hello,

My collegue made an error with the sh VTP counters.

So those are the good one.



110 -3750-01#sh vtp counter

VTP statistics:

Summary advertisements received : 232553

Subset advertisements received : 12

Request advertisements received : 88268

Summary advertisements transmitted : 407709

Subset advertisements transmitted : 88258

Request advertisements transmitted : 0

Number of config revision errors : 12906

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

---------------- ---------------- ---------------- ---------------------------

Gi1/0/1 0 0 0

Gi1/0/17 0 0 0

Gi1/0/24 0 0 0

Gi1/0/25 0 0 0

Gi1/0/26 0 0 0

Gi1/0/28 0 0 0


140 -3750-001#sh vtp counters

VTP statistics:

Summary advertisements received : 703927

Subset advertisements received : 12

Request advertisements received : 352310

Summary advertisements transmitted : 1406744

Subset advertisements transmitted : 352321

Request advertisements transmitted : 0

Number of config revision errors : 176247

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

---------------- ---------------- ---------------- ---------------------------

Gi1/0/21 0 0 0

Gi1/0/22 0 0 0

Gi1/0/23 0 0 0

Gi1/0/24 0 0 0

Gi1/0/25 0 0 0

Correct Answer
Kevin Dorrell Fri, 04/25/2008 - 07:23

Mmm. That is strange because it looks like the MD5 digest is different on the two switches. Sorry to insist, but are you sure there is not a VTP password? I have a synchronised domain, and I have the same MD5 digest on both server switches.


I presume these two switches are directly connected together via 3750-2 G1/0/25 to 3750-1 don't-know which port. Perhaps it would be useful to see the configs of the two ports connecting them together and a show cdp neighbor G1/0/25 detail.


Kevin Dorrell

Luxembourg


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