Multi-VLAN port vs Trunk port

[rsiegrist]

I have a switched network of C2980 & C3548 switches with multiple VLANs. I would like to understand the difference between Mulit-VLAN ports and trunk ports.

What circumstances would dictate using one over the other?

If I configure the router port as Multi-VLAN, does the router still require sub-interfaces?

Any information on this subject will be greatly appreciated

TIA, Bob

[bfetzer]

I replied earlier but cisco's page screwed up. here's a great page to get you started. I typed a big long easy explanation too, but that got eaten as well.

http://www.cisco.com/warp/public/793/lan_switching/3.html

[rsiegrist]

Thank you for the link, it was a good read. I understand the differences better (I think). Do I understand the document correctly...you can not have a multi-vlan port and a trunk port on the same switch? Or, not the same port? The C2980 swith does not support multi-Vlan. Would like to use multi-vlan to router and trunkng between switches. Last question this time around; Does the router interface get configured the same for multi-Vlan and trunking (intervlan routing)?

[Suryakant Shant]

The multi-vlan concept is only with Catalyst 2900XL/3500XL switches. So never say that you want to configure Multi-Vlan on a router.

Now if you have some 3548XL series switches and multiple VLANs are created on this switch. You can do interVlan routing by configuring a trunk port between this switch and the router. You have to create subinterfaces on the router for each and every VLAN created on Switch and assign the IP addresses from the respective VLANs to the subinterfaces.

This way you can do InterVLAN routing. Here is a good link which explains how to do InterVLAN routing on XL switch using a router.

http://www.cisco.com/warp/public/473/50.shtml

Let me know if this is what you were looking for.

[rsiegrist]

Thank you. Your link did clear up some things for me. In an effort to make the best educated decisions I still have a couple of questions.

First - Throughout the documentation I've read that you can not have a Multi-VLAN port on a switch with trunking (to other switches), is this a correct understanding?

Second - what are the pros/cons to using Multi-VLAN vs Trunking?

[kmuthukamu]

Refer this link. http://www.cisco.com/univercd/cc/td/doc/product/lan/c2900xl/29_35xu/olhelp/vlanmgmt.htm#Assigning')">http://www.cisco.com/univercd/cc/td/doc/product/lan/c2900xl/29_35xu/olhelp/vlanmgmt.htm#Assigning Multi-VLAN Ports to VLANs

This link will give u the difference.

http://www.cisco.com/warp/public/793/lan_switching/3.html#catalyst2935

[rsiegrist]

Thank you. These were excellent bits of information. I appreciate the assistance.

[Mohd Danish]

Hi ,

I understand the Multi-VLAN port configuration and concept  .

..but lIttle confuse about the traffic flow  , as I understand tagging is not used on Multi-VLAN ports then how switch will understand reverse traffic (from router/Server) to which vlan it belongs to.

Please clarify the inbound and outbound traffic flow in this case  .

Thanks

[paolo bevilacqua]

Mohd Danish wrote:
Hi ,
I understand the Multi-VLAN port configuration and concept  .
..but lIttle confuse about the traffic flow  , as I understand tagging is not used on Multi-VLAN ports then how switch will understand reverse traffic (from router/Server) to which vlan it belongs to.
 Please clarify the inbound and outbound traffic flow in this case  . 

You are responding to an 11 years old thread, about which by now people have moved on.

Please open new threads for new problems.

[Mohd Danish]

Oops

I just didnt notice it ....thanks to inform me Paolo .