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VLAN Miss match Discoverd om port ???????

Hi,

I have question that .. i have 2 switches of Catalyst3750. SWitch- and Sitch-2

there are certian Vlan exist on Lan switch-2 and connceted with switch 1 ans switcg-1 is connected with with router,

i am reciving Vlam mismmatch error on both swiches,

Switch -1 port 24 & 23 (valn 1 dfault Vlan) connect to switch-2 on port 22 & 24 which are in different Vlan..

So suggest me the solutions.

Thanks

6 REPLIES

Re: VLAN Miss match Discoverd om port ???????

could you please repost this question?

For what I could understand you connected 2 switches using ports 23/24 in sw1 and 22/24 in sw2, and they are configured with different vlans?

if you are connecting using :

switchport mode access

switchport access vlan

you need to use same vlan in both side in order to get it right

if you are connecting through trunk:

switchport mode trunk

switchport encap dot1q

and using default(permiting all vlans) you shouldnt be having any issues.

Please let us know what is the configs for these 4 ports.

Vlad

Re: VLAN Miss match Discoverd om port ???????

HI

i think u r trying to use this ports on the two switches as trunk ports and i assume u r using dot1q encapsulation so this message is normal as u r having different native vlans on the two switches.

as u have mentioned that on switch-1 port 24&23 are in vlan 1 and on switch-2 port 22&23 are in different vlan.so trying changeing the native vlan on the switches ensure that it is same at both the ends.

e.g on switch-1 if native vlan is vlan 1 then it should be same on switch 2.

Thanks

Mahmood

Re: VLAN Miss match Discoverd om port ???????

Hi Friend,

What you are doing is a VLAN leakage connecting 2 swithes with different vlans if your ports are configured as access ports.

If you have cautiously designed this network with some intention just disable cdp on the ports and you will not see this error message.

"no cdp enable" under interface configuration mode

If these ports are trunk ports and you have configured native vlans different then these vlans will not talk to each other at all so its as good as not having these vlans or having same native vlans both sides.

If you want to change native vlan and keep them same both sides issue this command on interface config mode

switchport trunk native vlan vlan-id

HTH, if yes please rate the post.

Ankur

Re: VLAN Miss match Discoverd om port ???????

Hi Friend,

What you are doing is a VLAN leakage connecting 2 swithes with different vlans if your ports are configured as access ports.

If you have cautiously designed this network with some intention just disable cdp on the ports and you will not see this error message.

"no cdp enable" under interface configuration mode

If these ports are trunk ports and you have configured native vlans different then these vlans will not talk to each other at all so its as good as not having these vlans or having same native vlans both sides.

If you want to change native vlan and keep them same both sides issue this command on interface config mode

switchport trunk native vlan vlan-id

HTH, if yes please rate the post.

Ankur

New Member

Re: VLAN Miss match Discoverd om port ???????

Hi,

I have read ur ans thank for the ans..

I havnt clear view about this still. i repeat it agian.

Two switches sw-1 (23 & 24) and sw-2 both are (22 & 24) connected.

No sw-1 there is no vlan just vlan 1(default vlan)

on sw-2 there are certian vlan and ports 22 &24 are in different vlan.

i am reciving Error native Vlan nmismatch discoverd on ports mention baove in both swtiches.

wht shuld u suggest for the solutions.

thanks

Re: VLAN Miss match Discoverd om port ???????

Hi Friend,

The first questions comes as why have you connected 2 switches together using 2 different vlans that is vlan 1 at one side and other vlans on other switch? Is there ny particular reason for such configuration if yes and you just want to get rid of this error message just disable CDP on the interfaces and you will not get this error messages.

Issue this command "no cdp enable" under interface config mode on the ports which are used o connect the 2 switches.

Or else keep vlans on ports same on 2 swithes which are used to connect the switches and configure etherchannel or else it will blcok one port because of STP.

HTH, if yes please rate the post.

Ankur

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