VMS Help LANCP, SET, DEVICE parameters, Qualifiers, /DISCOVERY_TIMER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /DISCOVERY_TIMER=value

    Sets the number of seconds to wait for a reply from a remote node
    when performing the source Token Ring routing route discovery
    process. The default value is 2 seconds.

    If you have nodes that respond slowly on your extended LAN, you
    may need to increase this number to reduce the amount of explorer
    traffic that traverses your LAN.