problem with vlans

[ccrespoh]

Hello,

I need to connect a trasparent device in the network. It's a traffic analyzer and it needs all the traffic pass through it.

I have two HSRP routers at the network output and I've created a vlan to connect one lan of the traffic analyzer with the routers, and another one to connect the other lan of the traffic analyzer with the firewall and other device.

It's working, but the catalyst 6000 series is logging a message of vlan error: "CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered".

How can I fix that problem? I mean, the systems are working fine, but I don't like that log message.

Thanks in advance.

[Prashanth Krishnappa · Accepted solution]

Disable CDP on the port connected to traffic analyzer.

Switch(config)#int fastEthernet x/y

Switch(config-if)#no cdp enable

[amit-singh]

These messages are generally reported when you have a trunk setup and the native vlan defers on either side of the link.

Please check if you have a differnt native vlan on the trunk. To define a native vlan on IOS switches go to interface config mode of the trunk link and use the comamnd" switchport trunk native vlan "

for Cat OS, the vlan in which the port was assigned prior to make as a trunk link,is the native vlan for that port.for examole if port was in vlan 3 and you make it as a trunk then Vlan 3 becomes the native vlan on that port.

The easiest way is to disable the CDP on that particular interface. For the IOS the command is no cdp enable

for the catOS its " set CDP x/x disable"

HTH,

-amit singh