Can we configure an 802.1Q trunk between two Cisco Catalyst switches on different sites over a MPLS connection?
A. When you connect to a remote site through MPLS, it is a layer 3 connection, and the 802.1Q trunk is a layer 2 protocol, so you cannot have an 802.1Q trunk across a MPLS connection. You need to have a Metro Ethernet connection or 802.1Q tunneling to expand your VLAN, which is provided by the ISP. In the MPLS cloud, the ISP communicates through VRF. Refer to Configuring IEEE 802.1Q Tunneling for more information.
