Hello, As a follow up to the discussion about the maximum number of routers in an ethernet network, I have written a stupid program which listens for DECNET hello packets and counts the number of nodes of each type. It is part of this github repo: https://github.com/jguillaumes/retroutils The project is DecnetListenerPlus, and it is meant to be opened using the NetBeans IDE (with the C/C++ plugins) but it can be built from the command line (using make/gmake). It runs under Linux (and probably under other unix-like systems) and requires root privileges. This is a (partial) output sample: Endnodes: 1, L1 routers: 0, L2 routers: 0 Endnodes: 1, L1 routers: 1, L2 routers: 0 Endnodes: 1, L1 routers: 1, L2 routers: 1 Endnodes: 2, L1 routers: 1, L2 routers: 1 Endnodes: 3, L1 routers: 1, L2 routers: 1 Endnodes: 3, L1 routers: 1, L2 routers: 2 Endnodes: 3, L1 routers: 2, L2 routers: 2 Endnodes: 3, L1 routers: 2, L2 routers: 3 Endnodes: 4, L1 routers: 2, L2 routers: 3 Endnodes: 5, L1 routers: 2, L2 routers: 3 Endnodes: 5, L1 routers: 2, L2 routers: 4 Endnodes: 6, L1 routers: 2, L2 routers: 4 Endnodes: 6, L1 routers: 3, L2 routers: 4 Endnodes: 7, L1 routers: 3, L2 routers: 4 Endnodes: 7, L1 routers: 3, L2 routers: 5 Endnodes: 8, L1 routers: 3, L2 routers: 5 Endnodes: 9, L1 routers: 3, L2 routers: 5 Endnodes: 10, L1 routers: 3, L2 routers: 5 Endnodes: 11, L1 routers: 3, L2 routers: 5 Endnodes: 12, L1 routers: 3, L2 routers: 5 Endnodes: 13, L1 routers: 3, L2 routers: 5 Endnodes: 14, L1 routers: 3, L2 routers: 5 Endnodes: 15, L1 routers: 3, L2 routers: 5 Endnodes: 16, L1 routers: 3, L2 routers: 5 Endnodes: 17, L1 routers: 3, L2 routers: 5 LEVEL 1 Routers Address: 7.61 , timer: 15 Address: 7.81 , timer: 10 Address: 19.40 , timer: 15 LEVEL 2 Routers Address: 8.400 , timer: 15 Address: 28.41 , timer: 15 Address: 42.1022, timer: 15 Address: 47.556 , timer: 15 Address: 62.637 , timer: 15 Endnodes Address: 1.21 , timer: 15 Address: 1.22 , timer: 15 Address: 1.301 , timer: 15 Address: 7.60 , timer: 15 Address: 7.70 , timer: 30 Address: 7.71 , timer: 15 Address: 7.72 , timer: 15 Address: 7.76 , timer: 15 Address: 8.401 , timer: 15 Address: 8.414 , timer: 15 Address: 8.444 , timer: 10 Address: 8.500 , timer: 10 Address: 14.1 , timer: 10 Address: 47.333 , timer: 10 Address: 47.559 , timer: 15 Address: 47.701 , timer: 15 Address: 62.5 , timer: 15