I am testing a configuration that utilizes two sets of mGRE tunnels to facilitate coms between each site and plan to implement label switching through each tunnel. My question is, when I issue the "sho mpls ldp discovery" command, I see that one of the tunnels is identified as xmit, and the other as xmit/recv. How is this determined? Can it be hard-set? Also, can bi-directional ldp discovery be implemented on both tunnels? Thanks in advance.