# Configuring EXP Bits for Differentiated Services

To set the initial value of the EXP bits to the UPC value associated with the packets:

- Issue the mpls copy-upc-to-exp command.
  host1(config)#mpls copy-upc-to-exp

To prevent the value of the EXP bits for a VPN/VC label from being modified by a per-LSP policy applied for the outer labels or by per-VR traffic class/color rules:

- Issue the mpls preserve-vpn-exp command.
  host1(config)#mpls preserve-vpn-exp

#### Related Documentation

- EXP Bits for Differentiated Services Overview
- Configuring MPLS and Differentiated Services
- Example Differentiated Services Application and Configuration
- mpls copy-upc-to-exp
- mpls preserve-vpn-exp