How do I connect a Cisco 2970 switch to a Cisco 4948 switch and pass two VLANs though?

I am trying to connect6 cisco 2970 switches to a 4948 backbone but need to be able to pass traffic though for one other vlan. Presently I am only able to pass the default vlan 1, but not able to pass a vlan 3 that I have configured for a DMZ. I am looking for the commands or some insight on how to make this work.
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You need to turn the ports that are connecting the switches together into a trunk

By default the trunk port should carry traffic to and from the switches for all vlans configured.

If you just want vlans 1 and 3 to go across you could specifically allow that by doing:

switchport trunk allowed vlan 1, 3

Do you have the vlans in the database on your backbone switch and other switches that need that traffic?
switchport trunk encap dot1q <--might not be needed depending on your software in the switch
switchport mode trunk
switchport nonegotiate
switchport trunk allowed vlan 1,3

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