Is Trunking Needed in this Configuration?

[mtgrech]

We have a backbone of three Catalyst 4006 switches, all connected at the Supe II module. The network has no VLAN's other than VLAN1. One switch was replaced with a 4507R and when it was configured the technician put the following trunking statements in the configuration for Gig1/1 and Gig2/1. Here is the excerpt from the config file:

interface GigabitEthernet1/1

switchport trunk encapsulation dot1q

switchport mode trunk

interface GigabitEthernet2/1

switchport trunk encapsulation dot1q

switchport mode trunk

Are the trunking statements needed? We don't use vlans, except vlan1 of course. The setup works, but can this cause problems?

Thanks for any assistance.

[wochanda]

A trunks job is to carry more than one VLAN between switches. Since you only have a single VLAN in your network, the trunk isn't really adding anything. It isn't subtracting anything either, because since all of your traffic is on Vlan1, and your trunk encapsulation is dot1q, all packets going over this link are untagged.

You can leave it be if you want, or you can change it back if you want, your choice.

[sachinraja]

yeah.. william is right.. but i would advice you to relook your design and bring a lot of useful concepts like VLAN, VTP, STP, trunking, VTP pruning etc on your LAN for on a good design perspective.. you will have easy management & less trouble even if you keep putting thousands of PCs after that.. trunking will be really useful then, when u have multiple VLANs on your network...

Raj