09-11-2006 10:48 AM - edited 03-03-2019 04:58 AM
Hi,
I want to extend the number of ports available in my network and have just purchased a Cisco 3560G. We have a Cisco 6509 running in Hybrid mode. The VTP mode on the 6509 is Transparent as we have created the VLANs and port assignments manually.
I want to add the new switch and have it hanging of port 6/8 on the Catalyst 6509.
Am I right if I set 6/8 to trunk with Gi0/1? I was ging to do the following in order to communicate between the two switches.
Set port 6/8 to trunking mode dot1q.
Create VLAN 150 and 151 on the 3560G. Add ports to each of the VLANS.
My confusion is this... if the trunk port is on one of the VLANs then the other VLAN will not be able to communicate over it. i.e. if I add the trunk into VLAN 151 then ports in VLAN 150 will not be able to send traffic over it.
What is the ideal way to set this up?
Thanks
Gavin
09-11-2006 11:00 AM
Gavin,
The trunk will forward all the common VLANs between the 2 switches. If you configured VLAN150 and VLAN151 manually on both switches, those VLANs will be included in the trunk along with the default VLAN1.
The ideal setup would be going with VTP Server/Client model.
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Please rate helpful posts.
Thanks
09-11-2006 11:31 AM
Just setup both sides as "desirable dot1q" and the trunk will be created and will carry all vlans . If you want you can manually prune off any vlans on the trunk that you don't want allowed across the trunk .
09-11-2006 12:10 PM
If I wanted to create an ether channel between the two switches, can I set the Etherchannel to dot1q trunk?
Gavin
09-11-2006 12:13 PM
You sure can.
09-11-2006 12:14 PM
Gavin,
Yes, you can.
All your trunk configuration needs to be configured under the port channel interface.
HTH
Sundar
09-11-2006 12:21 PM
Sorry about all these questions but....
if the native VLAN on the Catalyst is not VLAN 1 say VLAN150 how will his impact on my trunk.
Do I have to make any special changes on the new 3560G?
09-11-2006 12:42 PM
Set the native vlan to be the same on both ends. Mismatched native VLANs can create problems even if trunk connects.
802.1q doesn't tag native vlan frames. As such, anytime an untagged frame arrives the switch assumes that it belongs to that vlan. Let's say if the native vlan is set to 150 on one switch and the 2nd switch that receives an untagged ARP frame will assume the traffic came in on vlan 1 (default) and if the switch doesn't know the MAC then it would forward it to vlan 1 and trunk ports. As you can see it can create problems if there's mismatched native vlans.
Hope this helps!
09-11-2006 12:42 PM
You should match the native vlan on both sides.
09-11-2006 12:36 PM
Sundar,
I am also getting a message on the port that I have set trunking on... the message states that....
INCONSISTENT PORT TYPE....
The port is then blocked by STP....
Is this because spaning tree port fast is configured on the other interface?
Gav
09-11-2006 12:43 PM
Remove the spanning-tree portfast command from all the concerned ports.
09-11-2006 01:16 PM
thanks guys for all your help... i'll be trying out the config suggestions you have given.
this is a great learning tool
Thanks again
Gavin
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