This turned out to be a hardware problem after all - short in an ethernet cable. Though I don't understand how I got quite the symptoms I did, it has now all been working for a couple of days so I guess that was it.
Graham On 03/11/15 15:33, Graham Seaman wrote: > On 03/11/15 15:15, Renaud (Ron) OLGIATI wrote: >> On Tue, 3 Nov 2015 12:49:44 +0000 >> Graham Seaman <nav...@yahoo.co.uk> wrote: >> >>> For some years I've been using a debian system as my household >>> firewall/router. It's been sitting quietly working without any major >>> changes, but has suddenly stopped doing so following my last aptitude >>> update/upgrade. >> <snip> >>> Any suggestions? >> Why not use a dedicated firewall distribution, like IPCop ? > The same machine also acts as my mail server, backup manager, etc. > Because of that I'm fairly desperate to get it back up as soon as > possible (all my real mail is currently bouncing while I'm stuck on > yahoo-mail). > > There's also a more general kind of philosophical point: I started using > Linux because I hated the approach that says 'software is too complex > for normal people; if software fails, throw your device away and get a > new one'. In practice over time my understanding of it has got less, > not more - I've been completely left behind since the start of systemd, > which I suspect may have something to do with my current problems. All > the same, I still feel that with some help everything ought to be fixable. > > Graham > > >> >> Cheers, >> >> Ron.