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problem with trunk and vtp between router and switch

mvoss
Level 1
Level 1

I have a router and switch that I am trying to get setup with trunking and VTP. I believe the trunking is working but the output of some show commands makes me think otherwise. VTP is not working at all - both devices are in the same domain, using the same password but never exchange information.

Here is the router:

interface FastEthernet0/0

no ip address

speed 100

full-duplex

!

interface FastEthernet0/0.1

encapsulation dot1Q 1 native

ip address 172.18.4.1 255.255.255.0

ip nat inside

ip virtual-reassembly

!

interface FastEthernet0/0.2

encapsulation dot1Q 2

ip address 63.x.x0.9 255.255.255.252

ip nat outside

ip virtual-reassembly

no cdp enable

!

interface FastEthernet0/0.3

encapsulation dot1Q 3

ip address 20.x.x.183 255.255.255.0

ip nat outside

ip virtual-reassembly

no cdp enable

!

interface FastEthernet0/0.10

encapsulation dot1Q 10

ip address 20.x.x.185 255.255.255.240

rate-limit output 1496000 1500000 1500000 conform-action transmit exceed-action drop

no cdp enable

!

interface FastEthernet0/0.11

encapsulation dot1Q 11

ip address 172.18.5.1 255.255.255.0

ip nat inside

ip virtual-reassembly

rate-limit input 2000000 2000000 2000000 conform-action transmit exceed-action drop

rate-limit output 2000000 2000000 2000000 conform-action transmit exceed-action drop

sh vtp status:

VTP Version : 2

Configuration Revision : 1

Maximum VLANs supported locally : 256

Number of existing VLANs : 9

VTP Operating Mode : Server

VTP Domain Name : TEST

VTP Pruning Mode : Enabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0xBA 0xCB 0x9F 0xE0 0xC2 0x5D 0x21 0x3C

sh int trunk: <blank>

Here is the switch:

interface FastEthernet0

switchport mode trunk

duplex full

speed 100

!

interface FastEthernet1

switchport access vlan 2

!

interface FastEthernet2

switchport access vlan 3

!

interface Vlan1

ip address 172.18.4.2 255.255.255.0

sh vtp status:

VTP Version : 2

Configuration Revision : 0

Maximum VLANs supported locally : 8

Number of existing VLANs : 7

VTP Operating Mode : Client

VTP Domain Name : TEST

VTP Pruning Mode : Enabled

VTP V2 Mode : Disabled

VTP Traps Generation : Disabled

MD5 digest : 0xDA 0xCA 0x50 0xF0 0xAA 0x36 0xBF 0x67

sh int trunk:

Port Mode Encapsulation Status Native vlan

Fa0 on 802.1q trunking 1

Port Vlans allowed on trunk

Fa0 1-4094

Port Vlans allowed and active in management domain

Fa0 1-3

Port Vlans in spanning tree forwarding state and not pruned

Fa0 1-3

1 Accepted Solution

Accepted Solutions

glen.grant
VIP Alumni
VIP Alumni

There is no vtp between a router and a switch when trunking unless the router has one of the multi port WIc switching modules installed . The commands are there if you have that installed but if you don't it really doesn't have any meaning. Between a router and a switch you are just forcing a trunk on and no vtp is used.

View solution in original post

6 Replies 6

glen.grant
VIP Alumni
VIP Alumni

There is no vtp between a router and a switch when trunking unless the router has one of the multi port WIc switching modules installed . The commands are there if you have that installed but if you don't it really doesn't have any meaning. Between a router and a switch you are just forcing a trunk on and no vtp is used.

I just put in a 9 port POE switch WIC and there is still no VTP communication. It's just a router and switch setup so it's not that big a deal.

Any ideas why show int trunk is blank on the router?

padramas
Cisco Employee
Cisco Employee

Hello Michael,

Can you check whether you have correct VTP passwords on router/switch by doing a " sh vtp password "

if different you set both ends having the same password by " vtp password

[Edit] agreeing with glen, assuming that you are trying VTP on VTP supported switch modules or certain models like 7600 series

HTH

Padmanabhan

I checked the passwords about 20 times so I know I at least have that correct. :)

Glen's answer is what I was not hoping to hear but oh well.

Thanks for the help guys.

Is f0/0 part of that wic module ? If so then the setup may not be correct.

F0/0 is not part of the WIC module. It is just a built in fast Ethernet port.

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