[HECnet] Intermittent Connection with PyDECnet?

I haven't used TAP in ages; when I need bridging I use Johnny's bridge. But the message ("No hardware address") means that PyDECnet tried to find out the MAC address for the interface you mentioned and could not do so. You can avoid that by specifying an address explicitly. The error handling clearly is bad here. The issue is that you're using an old config file pattern that is no longer valid. I think I contributed to this by not cleaning up old config examples until recently. Some time ago I introduced the ability for a single PyDECnet process to run multiple DECnet nodes (systems), and for that matter bridges as well. This is done by using a config file per system. In the process, I didn't want HTTP access to be per node, so I pulled it into a separate part of the process. The way it works (see doc/config.txt) is that you may have several config files, and each contains an element that says what sort of thing it defines. Quoting config.txt: Each top level config file defines either a DECnet node (instance of "routing"), an Ethernet bridge, or the HTTP access feature. So each config file must contain either a "routing", a "bridge", or an "http" component -- one but not more than one of these. So what happened is that you started PyDECnet with an HTTP server but without nodes or bridges, so it has nothing to talk about. The config lines "circuit" and "node" and "system" are not relevant to the case of configuring the HTTP server so they were ignored. The bad error handling is that PyDECnet should complain if you didn't define at least one node or bridge. It would be nice if it also rejected lines that aren't relevant (such as circuit definitions in an HTTP server config file) but that's tricky because there isn't any order requirement for the config lines. In the example you gave, the type of config (http) isn't given until the last line. paul